Method and apparatus for transmitting or receiving wireless signal in wireless communication system

ABSTRACT

The present disclosure relates to a wireless communication system, and specifically, a method and an apparatus therefor, the method comprising: generating first A/N information for a first PDSCH group and second A/N information for a second PDSCH group, wherein each PDSCH group is a basic group for an A/N request; based on an A/N for a specific PDSCH not belonging to any PDSCH group being transmitted with the first and second A/N information, appending the A/N for the specific PDSCH after the first and second A/N information; and transmitting control information including the first and second A/N information and the A/N for the specific PDSCH.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/694,939, filed on Mar. 15, 2022, which is a continuation ofInternational Application No. PCT/KR2020/014121, filed on Oct. 15, 2020,which claims the benefit of an earlier filing date and right of priorityto U.S. Provisional Application No. 62/915,620, filed on Oct. 15, 2019,and U.S. Provisional Application No. 62/923,436, filed on Oct. 18, 2019,the contents of which are all hereby incorporated by reference herein intheir entirety.

TECHNICAL FIELD

The present disclosure relates to a wireless communication system, andin more detail, relates to a method and an apparatus of transmitting andreceiving a wireless signal in a wireless communication system.

BACKGROUND

Wireless communication systems have been widely deployed to providevarious types of communication services such as voice and data. Ingeneral, a wireless communication system is a multiple access systemthat can support communication with multiple users by sharing availablesystem resources (bandwidth, transmission power, etc.). Examples of themultiple access system include a code division multiple access (CDMA)system, a frequency division multiple access (FDMA) system, a timedivision multiple access (TDMA) system, an orthogonal frequency divisionmultiple access (OFDMA) system, and a single carrier frequency divisionmultiple access (SC-FDMA) system, etc.

SUMMARY

An object of the present disclosure is to provide a method and anapparatus of efficiently performing a wireless signaltransmission/reception process.

The technical objects to be achieved by the present disclosure are notlimited to the above-described technical objects, and other technicalobjects which are not described herein will be clearly understood bythose skilled in the pertinent art from the following description.

In a first aspect of the present disclosure, a method used by a userequipment (UE) in a wireless communication system is provided, themethod includes generating first acknowledgement/negativeacknowledgement (A/N) information for a first physical downlink sharedchannel (PDSCH) group and second A/N information for a second PDSCHgroup, wherein each PDSCH group is a basic group for an A/N request;based on an A/N for a specific PDSCH not belonging to any PDSCH groupbeing transmitted with the first and second A/N information, appendingthe A/N for the specific PDSCH after the first and second A/Ninformation; and transmitting control information including the firstand second A/N information and the A/N for the specific PDSCH.

In a second aspect of the present disclosure, a UE used in a wirelesscommunication system is provided, the UE may include at least onetransceiver; at least one processor; and at least one computer memoryoperatively connected to the at least one processor and, when executed,causing the at least one processor to perform an operation, theoperation includes generating first acknowledgement/negativeacknowledgement (A/N) information for a first physical downlink sharedchannel (PDSCH) group and second A/N information for a second PDSCHgroup, wherein each PDSCH group is a basic group for an A/N request;based on an A/N for a specific PDSCH not belonging to any PDSCH groupbeing transmitted with the first and second A/N information, appendingthe A/N for the specific PDSCH after the first and second A/Ninformation; and transmitting control information including the firstand second A/N information and the A/N for the specific PDSCH.

In a third aspect of the present disclosure, a device for a UE isprovided, the device may include at least one processor; and at leastone computer memory operatively connected to the at least one processorand, when executed, causing the at least one processor to perform anoperation, the operation includes generating firstacknowledgement/negative acknowledgement (A/N) information for a firstphysical downlink shared channel (PDSCH) group and second A/Ninformation for a second PDSCH group, wherein each PDSCH group is abasic group for an A/N request; based on an A/N for a specific PDSCH notbelonging to any PDSCH group being transmitted with the first and secondA/N information, appending the A/N for the specific PDSCH after thefirst and second A/N information; and transmitting control informationincluding the first and second A/N information and the A/N for thespecific PDSCH.

In a fourth aspect of the present disclosure, a computer-readable mediumstoring at least one computer program, when executed, causing the atleast one processor to perform an operation is provided, the operationincludes generating first acknowledgement/negative acknowledgement (A/N)information for a first physical downlink shared channel (PDSCH) groupand second A/N information for a second PDSCH group, wherein each PDSCHgroup is a basic group for an A/N request; based on an A/N for aspecific PDSCH not belonging to any PDSCH group being transmitted withthe first and second A/N information, appending the A/N for the specificPDSCH after the first and second A/N information; and transmittingcontrol information including the first and second A/N information andthe A/N for the specific PDSCH.

In a fifth aspect of the present disclosure, a method performed by abase station in a wireless communication system is provided, the methodincludes transmitting at least one PDSCH belonging to a first physicaldownlink shared channel (PDSCH) group and at least one PDSCH belongingto a second PDSCH group, wherein each PDSCH group is a basic group foran acknowledgement/negative acknowledgement (A/N) request; transmittinga specific PDSCH that does not belong to any PDSCH group; and receivingcontrol information including first A/N information for the first PDSCHgroup, second A/N information for a second PDSCH group, and an A/N forthe specific PDSCH, wherein the A/N for the specific PDSCH is locatedafter the first and second A/N information.

In a sixth aspect of the present disclosure, a base station used in awireless communication system is provided, the base station may includeat least one transceiver; at least one processor; and at least onecomputer memory operatively connected to the at least one processor and,when executed, causing the at least one processor to perform anoperation, the operation includes transmitting at least one PDSCHbelonging to a first physical downlink shared channel (PDSCH) group andat least one PDSCH belonging to a second PDSCH group, wherein each PDSCHgroup is a basic group for an acknowledgement/negative acknowledgement(A/N) request; transmitting a specific PDSCH that does not belong to anyPDSCH group; and receiving control information including first A/Ninformation for the first PDSCH group, second A/N information for asecond PDSCH group, and an A/N for the specific PDSCH, wherein the A/Nfor the specific PDSCH is located after the first and second A/Ninformation.

Preferably, the specific PDSCH may include a semi-persistent scheduling(SPS) PDSCH.

Preferably, A/N retransmission may be allowed for the first and secondA/N information, respectively, but A/N retransmission may not be allowedfor the A/N for the SPS PDSCH.

Preferably, receiving downlink control information (DCI) for PDSCHscheduling may be further included, and the DCI may include A/N requestinformation for the first PDSCH group and A/N request information forthe second PDSCH group.

Preferably, the control information may be transmitted in an unlicensedband.

According to the present disclosure, it is possible to efficientlytransmit and receive wireless signals in a wireless communicationsystem.

Effects achievable by the present disclosure are not limited to theabove-described effects, and other effects which are not describedherein may be clearly understood by those skilled in the pertinent artfrom the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Accompanying drawings included as part of detailed description forunderstanding the present disclosure provide embodiments of the presentdisclosure and describe technical features of the present disclosurewith detailed description.

FIG. 1 illustrates physical channels used in a 3GPP system, which is anexample of a wireless communication system, and a general signaltransmission method using them.

FIG. 2 illustrates a frame structure.

FIG. 3 illustrates a resource grid of a slot.

FIG. 4 illustrates a structure of a self-contained slot.

FIG. 5 illustrates an example in which a physical channel is mapped in aself-contained slot.

FIG. 6 illustrates the ACK/NACK transmission process.

FIG. 7 illustrates a PUSCH (Physical Uplink Shared Channel) transmissionprocess.

FIG. 8 illustrates an example of multiplexing control information toPUSCH.

FIGS. 9A and 9B illustrate a wireless communication system supporting anunlicensed band.

FIG. 10 illustrates a method for occupying a resource in an unlicensedband.

FIG. 11 illustrates a flow chart of Type 1 CAP operation of a userequipment for uplink signal transmission.

FIGS. 12A to 14 illustrate A/N transmission according to an embodimentof the present disclosure.

FIG. 15 illustrates semi-persistent scheduling (SPS).

FIG. 16 illustrates an A/N payload configuration based on a Type-2codebook.

FIG. 17 illustrates a problem in simultaneous transmission of an A/N fora SPS PDSCH.

FIGS. 18 to 19 illustrates A/N transmission according to an embodimentof the present disclosure.

FIGS. 20 to 23 illustrates a communication system (1) and a wirelessdevice applied to the present disclosure.

DETAILED DESCRIPTION

The following description may be used for a variety of radio accesssystems such as code division multiple access (CDMA), frequency divisionmultiple access (FDMA), time division multiple access (TDMA), orthogonalfrequency division multiple access (OFDMA), single carrier frequencydivision multiple access (SC-FDMA), etc. CDMA may be implemented by aradio technology such as Universal Terrestrial Radio Access (UTRA) orCDMA2000. TDMA may be implemented by a radio technology such as GlobalSystem for Mobile communications (GSM)/General Packet Radio Service(GPRS)/Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may beimplemented by a radio technology such as IEEE 802.11 (Wi-Fi), IEEE802.16 (WiMAX), IEEE 802-20, Evolved UTRA (E-UTRA), etc. UTRA is a partof the Universal Mobile Telecommunications System (UMTS). 3GPP (3rdGeneration Partnership Project) long term evolution (LTE) is a part ofan Evolved UNITS (E-UMTS) using E-UTRA and LTE-A (Advanced) is anadvanced version of 3GPP LTE. 3GPP NR (New Radio or New Radio AccessTechnology) is an advanced version of 3GPP LTE/LTE-A.

As more communication devices have required a higher capacity, a needfor an improved mobile broadband communication compared to the existingradio access technology (RAT) has emerged. In addition, massive MTC(Machine Type Communications) providing a variety of services anytimeand anywhere by connecting a plurality of devices and things is also oneof main issues which will be considered in a next-generationcommunication. Furthermore, a communication system design considering aservice/a terminal sensitive to reliability and latency is alsodiscussed. As such, introduction of a next-generation RAT consideringeMBB (enhanced mobile broadband communication), mMTC (massive MTC),URLLC (Ultra-Reliable and Low Latency Communication), etc. is discussedand, for convenience, a corresponding technology is referred to as NR inthe present disclosure.

To clarify description, it is described based on a 3GPP NR, but atechnical idea of the present disclosure is not limited thereto.

In a wireless communication system, a user equipment receivesinformation through a downlink (DL) from a base station, and a userequipment transmits information through an uplink (UL) to a basestation. Information transmitted and received between a base station anda user equipment includes data and various control information, andvarious physical channels exist according to the type/use of theinformation they transmit and receive.

FIG. 1 illustrates physical channels used in a 3GPP NR system, and ageneral signal transmission method using them.

When a terminal is turned on or newly enters a cell in a state in whichthe terminal was turned off, it performs an initial cell search byincluding synchronization with a base station or the like in step S101.For the initial cell search, a terminal receives a synchronizationsignal block (SSB) from a base station. SSB includes a primarysynchronization signal (PSS), a secondary synchronization signal (SSS)and a physical broadcast channel (PBCH). A terminal synchronizes with abase station based on PSS/SSS, and obtains information such as cellidentifier (ID), etc. In addition, a terminal may obtain broadcastinginformation in a cell based on a PBCH. Meanwhile, a terminal may checkout a downlink channel state by receiving a downlink reference signal(DL RS) at an initial cell search stage.

A terminal which completed an initial cell search may obtain moredetailed system information by receiving a physical downlink controlchannel (PDCCH) and a physical downlink shared channel (PDSCH) accordingto a physical downlink control channel in step S102.

Thereafter, a terminal may perform a random access procedure such assteps S103 to S106 to complete access to a base station. For the randomaccess procedure, a terminal may transmit a preamble through a physicalrandom access channel (PRACH) (S103), and may receive a response messageto a preamble through a physical downlink control channel and acorresponding physical downlink shared channel (S104). In a case ofcontention based random access, a contention resolution procedure may beperformed such as transmission of an additional physical random accesschannel (S105) and reception of a physical downlink control channel anda corresponding physical downlink shared channel (S106).

A terminal which performed the above-described procedure subsequentlymay perform a physical downlink control channel/a physical downlinkshared channel reception (S107) and a physical uplink shared channel(PUSCH)/a physical uplink control channel (PUCCH) transmission (S108) asa general uplink/downlink signal transmission procedure. Controlinformation transmitted by a terminal to a base station is referred toas uplink control information (UCI). UCI includes a Hybrid AutomaticRepeat and reQuest Acknowledgment/Negative-ACK (HARQ ACK/NACK), aScheduling Request (SR), a Channel State Information (CSI), etc. CSIincludes a Channel Quality Indicator (CQI), a Precoding Matrix Indicator(PMI), a Rank Indication (RI), etc. The UCI is generally transmittedthrough PUCCH, but may be transmitted through PUSCH when controlinformation and traffic data are to be transmitted at the same time. Inaddition, the UCI may be transmitted aperiodically through PUSCHaccording to a request/indication of a network.

FIG. 2 illustrates a frame structure. In NR, uplink and downlinktransmission is configured as frames. Each radio frame has a length of10 ms and is divided into two 5 ms half-frames (HF). Each half-frame isdivided into 5 1 ms subframes (SFs). A subframe is divided into one ormore slots, and the number of slots in a subframe depends on subcarrierspacing (SCS). Each slot includes 12 or 14 Orthogonal Frequency DivisionMultiplexing (OFDM) symbols according to a cyclic prefix (CP). When anormal CP is used, each slot includes 14 OFDM symbols. When an extendedCP is used, each slot includes 12 OFDM symbols.

Table 1 illustrates that the number of symbols per slot, the number ofslots per frame, and the number of slots per subframe vary according toSCS when a normal CP is used.

TABLE 1 SCS (15*2{circumflex over ( )}u) N^(slot) _(symb) N^(frame,u)_(slot) N^(subframe,u) _(slot)  15 KHz (u = 0) 14 10 1  30 KHz (u = 1)14 20 2  60 KHz (u = 2) 14 40 4 120 KHz (u = 3) 14 80 8 240 KHz (u = 4)14 160 16 *N^(slot) _(symb): number of symbols in a slot *N^(frame,u)_(slot): the number of slots in a frame *N^(subframe,u) _(slot): thenumber of slots in a subframe

Table 2 illustrates that the number of symbols per slot, the number ofslots per frame, and the number of slots per subframe vary according toSCS, when an extended CP is used.

TABLE 2 SCS (15*2{circumflex over ( )}u) N^(slot) _(symb) N^(frame,u)_(slot) N^(subframe,u) _(slot) 60 KHz (u = 2) 12 40 4

A structure of a frame is merely an example, and the number ofsubframes, the number of slots, and the number of symbols in a frame maybe variously changed.

In a NR system, OFDM numerology (e.g., SCS) may be configureddifferently between a plurality of cells aggregated into one UE.Accordingly, an (absolute time) duration of a time resource (e.g., SF,slot, or TTI) (referred to as TU (Time Unit) for convenience) composedof the same number of symbols may be configured differently betweenaggregated cells. Here, the symbol may include an OFDM symbol (or aCP-OFDM symbol) and an SC-FDMA symbol (or a Discrete FourierTransform-spread-OFDM, DFT-s-OFDM symbol).

FIG. 3 illustrates a resource grid of a slot. A slot includes aplurality of symbols in a time domain. For example, in the case of anormal CP, one slot includes 14 symbols, but in the case of an extendedCP, one slot includes 12 symbols. The carrier includes a plurality ofsubcarriers in a frequency domain. A resource block (RB) is defined as aplurality (e.g., 12) of consecutive subcarriers in a frequency domain. Abandwidth part (BWP) is defined as a plurality of consecutive physicalRBs (PRBs) in a frequency domain, and may correspond to one numerology(e.g., SCS, CP length, etc.). A carrier may include a maximum of N(e.g., 5) BWPs. Data communication is performed through an activatedBWP, and only one BWP can be activated for one UE. Each element in theresource grid is referred to as a resource element (RE), and one complexsymbol may be mapped.

FIG. 4 illustrates a structure of a self-contained slot. In a NR system,a frame is characterized by a self-contained structure in which a DLcontrol channel, DL or UL data, and a UL control channel can all beincluded in one slot. For example, the first N symbols in a slot may beused to transmit a DL control channel (hereinafter, DL control region),and the last M symbols in a slot may be used to transmit a UL controlchannel (hereinafter, UL control region). N and M are each an integergreater than or equal to 0. A resource region (hereinafter, referred toas a data region) between the DL control region and the UL controlregion may be used for DL data transmission or for UL data transmission.A time gap for DL-to-UL or UL-to-DL switching may exist between thecontrol region and the data region. As an example, the followingconfiguration may be considered. Each duration is listed inchronological order.

-   -   1. DL only configuration    -   2. UL only configuration    -   3. Mixed UL-DL configuration        -   DL region+Guard Period (GP)+UL control region        -   DL control region+GP+UL region        -   DL region: (i) DL data region, (ii) DL control region+DL            data region        -   UL region: (i) UL data region, (ii) UL data region+UL            control region

FIG. 5 illustrates an example in which a physical channel is mapped in aself-contained slot. A PDCCH may be transmitted in a DL control region,and a PDSCH may be transmitted in a DL data region. A PUCCH may betransmitted in a UL control region, and a PUSCH may be transmitted in aUL data region. A GP provides a time gap in the process of a basestation and a UE switching from a transmission mode to a reception modeor in the process of switching from a reception mode to a transmissionmode. Some symbols of the time of switching from DL to UL in a subframemay be configured to GP.

Hereinafter, each physical channel will be described in more detail.

A PDCCH carries Downlink Control Information (DCI). For example, PCCCH(i.e., DCI) carries a transmission format and resource allocation of adownlink shared channel (DL-SCH), resource allocation information for anuplink shared channel (UL-SCH), paging information for a paging channel(PCH), system information on a DL-SCH, resource allocation informationfor a higher layer control message such as a random access responsetransmitted on a PDSCH, a transmission power control command,activation/deactivation of Configured Scheduling (CS), etc. DCI includesa cyclic redundancy check (CRC), and a CRC is masked/scrambled withvarious identifiers (e.g., Radio Network Temporary Identifier, RNTI)according to an owner or use purpose of a PDCCH. For example, if a PDCCHis for a specific UE, a CRC is masked with a UE identifier (e.g.,Cell-RNTI, C-RNTI). If a PDCCH relates to paging, a CRC is masked with aPaging-RNTI (P-RNTI). If a PDCCH relates to system information (e.g.,System Information Block, SIB), a CRC is masked with a SystemInformation RNTI (SI-RNTI). If a PDCCH relates to a random accessresponse, a CRC is masked with a random access-RNTI (RA-RNTI).

A PDCCH is configured as 1, 2, 4, 8, 16 CCEs (Control Channel Elements)according to an Aggregation Level (AL). A CCE is a logical allocationunit used to provide a PDCCH of a predetermined code rate according to aradio channel state. A CCE includes 6 REGs (Resource Element Groups). AREG is defined by one OFDM symbol and one (P)RB. A PDCCH is transmittedthrough a control resource set (CORESET). A CORESET is defined as a setof REGs with a given numerology (e.g., SCS, CP length, etc.). Aplurality of CORESETs for one UE may overlap in a time/frequency domain.A CORESET may be configured by system information (e.g., MasterInformation Block, MIB) or UE-specific higher layer (e.g., RadioResource Control, RRC, layer) signaling. Specifically, the number of RBsand the number of OFDM symbols (maximum 3) included CORESET may beconfigured by higher layer signaling.

For PDCCH reception/detection, a UE monitors PDCCH candidates. A PDCCHcandidate represents CCE(s) that a UE is required to monitor for PDCCHdetection. Each PDCCH candidate is defined as 1, 2, 4, 8, or 16 CCEsaccording to an AL. Monitoring includes (blind) decoding of PDCCHcandidates. A set of PDCCH candidates monitored by a UE is defined as aPDCCH search space (SS). A search space includes a common search space(CSS) or a UE-specific search space (USS). A UE may acquire DCI bymonitoring PDCCH candidates in one or more search spaces configured byMIB or higher layer signaling. Each CORESET is associated with one ormore search spaces, and each search space is associated with oneCORESET. A search space may be defined based on the followingparameters.

-   -   controlResourceSetId: indicates a CORESET associated with a        search space    -   monitoringSlotPeriodicityAndOffset: indicates a PDCCH monitoring        period (slot unit) and a PDCCH monitoring duration offset (slot        unit)    -   monitoringSymbolsWithinSlot: indicates the PDCCH monitoring        symbol in the slot (eg indicates the first symbol(s) of CORESET)    -   nrofCandidates: indicates the number of PDCCH candidates (one of        0, 1, 2, 3, 4, 5, 6, 8) for each AL={1, 2, 4, 8, 16}    -   An occasion (e.g., time/frequency resource) to monitor PDCCH        candidates is defined as a PDCCH (monitoring) occasion. One or        more PDCCH (monitoring) occasions may be configured within a        slot.

Table 3 illustrates the features of each search space type

TABLE 3 Type Search Space RNTI Use Case Type0-PDCCH Common SI-RNTI on aSIB Decoding primary cell Type0A-PDCCH Common SI-RNTI on a SIB Decodingprimary cell Type1-PDCCH Common RA-RNTI or TC- Msg2, Msg4 RNTI on adecoding in RACH primary cell Type2-PDCCH Common P-RNTI on a PagingDecoding primary cell Type3-PDCCH Common INT-RNTI, SFI- RNTI, TPC-PUSCH-RNTI, TPC-PUCCH- RNTI, TPC-SRS- RNTI, C-RNTI, MCS-C-RNTI, orCS-RNTI(s) UE Specific C-RNTI, or MCS- User specific C-RNTI, or CS-PDSCH decoding RNTI(s)

Table 4 illustrates DCI formats transmitted on a PDCCH.

TABLE 4 DCI format Usage 0_0 Scheduling of PUSCH in one cell 0_1Scheduling of PUSCH in one cell 1_0 Scheduling of PDSCH in one cell 1_1Scheduling of PDSCH in one cell 2_0 Notifying a group of UEs of the slotformat 2_1 Notifying a group of UEs of the PRB(s) and OFDM symbol(s)where UE may assume no transmission is intended for the UE 2_2Transmission of TPC commands for PUCCH and PUSCH 2_3 Transmission of agroup of TPC commands for SRS transmissions by one or more UEs

DCI format 0_0 may be used for scheduling a TB-based (or TB-level)PUSCH, and DCI format 0_1 may be used for scheduling a TB-based (orTB-level) PUSCH or a CBG (Code Block Group)-based (or CBG-level) PUSCH.DCI format 1_0 may be used for scheduling a TB-based (or TB-level)PDSCH, and DCI format 1_1 may be used for scheduling a TB-based (orTB-level) PDSCH or a CBG-based (or CBG-level) PDSCH (DL grant DCI). DCIformat 0_0/0_1 may be referred to as UL grant DCI or UL schedulinginformation, and DCI format 1_0/1_1 may be referred to as DL grant DCIor UL scheduling information. DCI format 2_0 is used for transmittingdynamic slot format information (e.g., dynamic SFI) to a UE, and DCIformat 2_1 is used for transmitting downlink pre-emption information toa UE. DCI format 2_0 and/or DCI format 2_1 may be transmitted to userequipments in a corresponding group through a group common PDCCH, whichis a PDCCH transmitted to UEs defined as one group.

DCI format 0_0 and DCI format 1_0 may be referred to as a fallback DCIformat, and DCI format 0_1 and DCI format 1_1 may be referred to as anon-fallback DCI format. A fallback DCI format has the same DCIsize/field configuration regardless of a UE configuration. On the otherhand, a non-fallback DCI format has a different DCI size/fieldconfiguration according to a UE configuration.

A PDSCH carries downlink data (e.g., DL-SCH transport block, DL-SCH TB),and modulation methods such as QPSK (Quadrature Phase Shift Keying), 16QAM (Quadrature Amplitude Modulation), 64 QAM, 256 QAM, etc. are appliedto the PDSCH. A codeword is generated by encoding a TB. A PDSCH cancarry up to two codewords. Scrambling and modulation mapping areperformed for each codeword, and modulation symbols generated from eachcodeword may be mapped to one or more layers. Each layer is mapped to aresource together with a demodulation reference signal (DMRS), isgenerated as an OFDM symbol signal, and is transmitted through acorresponding antenna port.

A PUCCH carries Uplink Control Information (UCI). UCI includes:

-   -   SR (Scheduling Request): It is information used to request a        UL-SCH resource.    -   Hybrid Automatic Repeat reQuest (HARQ)-ACK (Acknowledgment): It        is a response to a downlink data packet (e.g., codeword) on the        PDSCH. It indicates whether a downlink data packet has been        successfully received. 1 bit of HARQ-ACK may be transmitted in        response to a single codeword, and 2 bits of HARQ-ACK may be        transmitted in response to two codewords. A HARQ-ACK response        includes positive ACK (simply, ACK), negative ACK (NACK), DTX or        NACK/DTX. Here, HARQ-ACK includes HARQ ACK/NACK and ACK/NACK.    -   CSI (Channel State Information): It is feedback information for        a downlink channel. Multiple Input Multiple Output        (MIMO)-related feedback information includes a Rank Indicator        (RI) and a Precoding Matrix Indicator (PMI).

Table 5 illustrates PUCCH formats. According to the PUCCH transmissionlength, it can be divided into Short PUCCH (formats 0, 2) and Long PUCCH(formats 1, 3, 4).

TABLE 5 PUCCH Length in OFDM Number of format symbols bits Usage Etc 01-2 ≤2 HARQ, SR Sequence selection 1  4-14 ≤2 HARQ, [SR] Sequencemodulation 2 1-2 >2 HARQ, CSI, [SR] CP-OFDM 3  4-14 >2 HARQ, CSI, [SR]DFT-s-OFDM (no UE multiplexing) 4  4-14 >2 HARQ, CSI, [SR] DFT-s-OFDM(Pre DFT OCC)

PUCCH format 0 carries UCI having a maximum size of 2 bits, and ismapped based on a sequence and transmitted. Specifically, a UE transmitsspecific UCI to a base station by transmitting one of a plurality ofsequences through a PUCCH with PUCCH format 0. A UE transmits a PUCCHwith PUCCH format 0 in a PUCCH resource for configuring a correspondingSR only when transmitting a positive SR.

PUCCH format 1 carries UCI having a maximum size of 2 bits, and amodulation symbol is spread by an orthogonal cover code (OCC) (which isconfigured differently according to whether or not frequency hopping isperformed) in a time domain. A DMRS is transmitted in a symbol in whicha modulation symbol is not transmitted (that is, time divisionmultiplexing (TDM) is performed and transmitted).

PUCCH format 2 carries UCI having a bit size greater than 2 bits, and amodulation symbol is transmitted by frequency division multiplexing(FDM) with a DMRS. A DM-RS is located at symbol indexes #1, #4, #7, and#10 in a given resource block with a density of ⅓. A Pseudo Noise (PN)sequence is used for a DM_RS sequence. For 2-symbol PUCCH format 2,frequency hopping may be activated.

In PUCCH format 3, UE multiplexing is not performed in the same physicalresource blocks, and the PUCCH format 3 carrier UCI having a bit sizegreater than 2 bits. In other words, a PUCCH resource of PUCCH format 3does not include an orthogonal cover code. A modulation symbol istransmitted by time division multiplexing (TDM) with a DMRS.

PUCCH format 4 supports multiplexing up to 4 UEs in the same physicalresource blocks, and carries UCI having a bit size greater than 2 bits.In other words, a PUCCH resource of PUCCH format 3 includes anorthogonal cover code. The modulation symbol is transmitted by timedivision multiplexing (TDM) with a DMRS.

A PUSCH carries uplink data (e.g., UL-SCH transport block, UL-SCH TB)and/or uplink control information (UCI), and is transmitted based on aCP-OFDM (Cyclic Prefix-Orthogonal Frequency Division Multiplexing)waveform or a DFT-s-OFDM (Discrete Fourier Transform-spread-OrthogonalFrequency Division Multiplexing) waveform. When a PUSCH is transmittedbased on a DFT-s-OFDM waveform, a UE transmits a PUSCH by applyingtransform precoding. For example, when transform precoding is notpossible (e.g., transform precoding is disabled), a UE transmits a PUSCHbased on a CP-OFDM waveform, and when transform precoding is possible(e.g., transform precoding is enabled), a UE transmits a PUSCH based ona CP-OFDM waveform or a DFT-s-OFDM waveform. PUSCH transmission may bedynamically scheduled by a UL grant in DCI, or scheduled based on higherlayer (e.g., RRC) signaling (and/or Layer 1 (L1) signaling (e.g.,PDCCH)) semi-statically (configured grant). PUSCH transmission may beperformed on a codebook-based transmission or a non-codebook-basedtransmission.

FIG. 6 illustrates the ACK/NACK transmission process. Referring to FIG.6 , a UE may detect a PDCCH in slot #n. Here, a PDCCH includes downlinkscheduling information (e.g., DCI formats 1_0 and 1_1), and the PDCCHindicates a DL assignment-to-PDSCH offset (K0) and a PDSCH-HARQ-ACKreporting offset (K1). For example, DCI formats 1_0 and 1_1 may includethe following information.

-   -   Frequency domain resource assignment: indicates a RB set        allocated to a PDSCH    -   Time domain resource assignment: K0, indicates a starting        position (e.g., OFDM symbol index) and a length (e.g., number of        OFDM symbols) of a PDSCH in a slot    -   PDSCH-to-HARQ_feedback timing indicator: indicates K1    -   HARQ process number (4 bits): indicates a HARQ process ID        (Identity) for data (e.g., PDSCH, TB)

Thereafter, a UE may receive a PDSCH in a slot #(n+K0) according toscheduling information of slot #n, and then transmit UCI through PUCCHin a slot #(n+K1). Here, UCI includes a HARQ-ACK response for a PDSCH.If a PDSCH is configured to transmit up to 1 TB, a HARQ-ACK response maybe configured with 1-bit. When a PDSCH is configured to transmit up to 2TBs, a HARQ-ACK response may be configured with 2-bits when spatialbundling is not configured, and may be configured with 1-bits whenspatial bundling is configured. When the HARQ-ACK transmission time fora plurality of PDSCHs is designated as a slot #(n+K1), UCI transmittedin a slot #(n+K1) includes HARQ-ACK responses for the plurality ofPDSCHs.

A plurality of parallel DL HARQ processes exist for DL transmission in abase station/UE. A plurality of parallel HARQ processes allow DLtransmissions to be performed continuously while waiting for HARQfeedback on successful or unsuccessful reception of previous DLtransmission. Each HARQ process is associated with a HARQ buffer of aMAC (Medium Access Control) layer. Each DL HARQ process manages statevariables related to the number of transmissions of a MAC PDU (PhysicalData Block) in a buffer, HARQ feedback for a MAC PDU in a buffer, and acurrent redundancy version, etc. Each HARQ process is identified by aHARQ process ID.

FIG. 7 illustrates a PUSCH (Physical Uplink Shared Channel) transmissionprocess. Referring to FIG. 7 , a UE may detect a PDCCH in a slot #n.Here, a PDCCH includes uplink scheduling information (e.g., DCI formats0_0, 0_1). DCI formats 0_0 and 0_1 may include the followinginformation.

-   -   Frequency domain resource assignment: indicates a set of RBs        allocated to a PUSCH    -   Time domain resource assignment: indicates a slot offset K2, a        starting position (e.g., symbol index) and a length (e.g.,        number of OFDM symbols) of a PUSCH in a slot. A start symbol and        a length may be indicated through a Start and Length Indicator        Value (SLIV) or may be indicated respectively.

Thereafter, a UE may transmit a PUSCH in a slot #(n+K2) according toscheduling information of a slot #n. Here, PUSCH includes UL-SCH TB.

FIG. 8 illustrates an example of multiplexing UCI to PUSCH. When aplurality of PUCCH resources and PUSCH resources overlap within a slotand simultaneous PUCCH-PUSCH transmission is not configured, UCI may betransmitted through PUSCH as shown (UCI piggyback or PUSCH piggyback).FIG. 8 illustrates a case in which HARQ-ACK and CSI are carried on aPUSCH resource.

FIGS. 9A and 9B illustrate a wireless communication system supporting anunlicensed band. For convenience, a cell operating in a licensed band(hereinafter, L-band) is defined as an LCell, and a carrier of the LCellis defined as a (DL/UL) Licensed Component Carrier (LCC). In addition, acell operating in an unlicensed band (hereinafter, U-band) is defined asa UCell, and a carrier of the UCell is defined as an (DL/UL) UnlicensedComponent Carrier (UCC). A carrier of a cell may mean an operatingfrequency (e.g., a center frequency) of the cell. A cell/carrier (e.g.,Component Carrier, CC) may be referred to as a cell.

When carrier aggregation (CA) is supported, one UE may transmit/receivea signal to/from a base station through a plurality of aggregatedcells/carriers. When a plurality of CCs are configured for one UE, oneCC may be configured as a PCC (Primary CC), and the remaining CCs may beconfigured as SCCs (Secondary CC). Specific control information/channel(e.g., CSS PDCCH, PUCCH) may be configured to be transmitted/receivedonly through a PCC. Data may be transmitted and received through aPCC/SCC. FIG. 9A illustrates a case in which a UE and a base stationtransmit and receive signals through an LCC and a UCC (non-standalone(NSA) mode). In this case, an LCC may be configured to a PCC and a UCCmay be configured to a SCC. When a plurality of LCCs are configured in aUE, one specific LCC may be configured as a PCC and the remaining LCCsmay be configured as SCCs. FIG. 9A corresponds to LAA of a 3GPP LTEsystem. FIG. 9B illustrates a case in which a UE and a base stationtransmit and receive signals through one or more UCCs without any LCC(standalone mode (SA)). In this case, one of the UCCs may be configuredas a PCC and the other UCCs may be configured as SCCs. Accordingly,PUCCH, PUSCH, PRACH transmission, etc. may be supported in a NR UCell.In an unlicensed band of a 3GPP NR system, both an NSA mode and an SAmode may be supported.

FIG. 10 illustrates a method for occupying a resource in an unlicensedband. According to regional regulations on unlicensed bands,communication nodes in unlicensed bands should determine whether othercommunication node(s) use channels before signal transmission.Specifically, a communication node may first perform CS (CarrierSensing) before transmitting a signal to check whether othercommunication node(s) are transmitting a signal. A case in which it isdetermined that other communication node(s) does not transmit a signalis defined as CCA (Clear Channel Assessment) has been confirmed. Ifthere is a pre-defined CCA threshold or a CCA threshold configured byhigher layer (e.g., RRC) signaling, a communication node determineschannel state as busy if energy higher than the CCA threshold isdetected in a channel, otherwise channel state may be considered asidle. For reference, in the Wi-Fi standard (802.11ac), a CCA thresholdis defined as −62 dBm for a non-Wi-Fi signal and −82 dBm for a Wi-Fisignal. If it is determined that channel state is idle, a communicationnode may start transmitting a signal in a UCell. The above-describedseries of procedures may be referred to as a Listen-Before-Talk (LBT) ora Channel Access Procedure (CAP). A LBT and a CAP may be equivalent.

In Europe, two LBT operations are exemplified as FBE (Frame BasedEquipment) and LBE (Load Based Equipment). In FBE, a channel occupancytime (e.g., 1-10 ms), which means the time during which a communicationnode can continue to transmit when the communication node succeeds inaccessing a channel, and an idle period corresponding to at least 5% ofthe channel occupancy time are included in one fixed frame, and CCA isdefined as an operation of observing a channel during a CCA slot (atleast 20 s) at the end of the idle period. A communication nodeperiodically performs CCA in units of fixed frames, and when a channelis unoccupied, it transmits data during a channel occupied time, andwhen a channel is occupied, it waits until a CCA slot of a next cycle.

On the other hand, in the case of LBE, a communication node firstconfigures a value of q∈{4, 5, . . . , 32}, and then performs CCA forone CCA slot. When a channel is unoccupied in a first CCA slot, data canbe transmitted by securing time of maximum (13/32)q ms length. If achannel is occupied in a first CCA slot, a communication node randomlyselects a value of NE{1, 2, . . . , q} and stores it as an initial valueof a counter, and then while sensing channel state in units of CCAslots, when a channel is unoccupied in units of CCA slots, the valuestored in the counter is decremented by one. When the counter valuebecomes 0, a communication node may transmit data by securing a time ofmaximum (13/32)q ms length.

Specifically, a plurality of CAP Type (i.e., LBT Type) for uplinktransmission in an unlicensed band may be defined. For example, a Type 1or Type 2 CAP may be defined for uplink transmission. A UE may perform aCAP (e.g., Type 1 or Type 2) configured/indicated by a base station foruplink signal transmission.

(1) Type 1 Uplink CAP Method

FIG. 11 illustrates a flow chart of Type 1 CAP operation of a UE foruplink signal transmission.

A UE may initiate a CAP for signal transmission through an unlicensedband (S1510). A UE may arbitrarily select a backoff counter N within acontention window (CW) according to step 1. Here, a value of N isconfigured to an initial value N_(init) (S1520). N_(init) is selected tobe any value between 0 and CW_(p). Then, according to step 4, if abackoff counter value (N) is 0 (S1530; Y), a UE ends a CAP process(S1532). Thereafter, a UE may perform Tx burst transmission (S1534). Onthe other hand, if a backoff counter value is not 0 (S1530; N), a UEdecreases a backoff counter value by 1 according to step 2 (S1540).Thereafter, a UE checks whether a channel of a UCell(s) is in an idlestate (S1550), and if a channel is in an idle state (S1550; Y), checkswhether a backoff counter value is 0 (S1530). On the other hand, if achannel is not in an idle state in step S1550, that is, if a channel isin a busy state (S1550; N), a UE checks whether a corresponding channelis in an idle state for a delay period (defer duration Td; 25 usec ormore) longer than a slot time (e.g., 9 us) according to step 5 (S1560).If a channel is in an idle state during a delay period (S1570; Y), a UEmay resume a CAP process again. Here, a delay period may include a 16usec period and m_(p) consecutive slot times (e.g., 9 us) immediatelyfollowing it. On the other hand, if a channel is in a busy state duringa delay period (S1570; N), a UE re-performs step S1560 to check againwhether a channel is in an idle state during a new delay period.

Table 6 shows m_(p), minimum CW (CW_(min,p)), maximum CW (CW_(max,p)),maximum channel occupancy time (MCOT, T_(ulmcot,p)) applied to a CAPaccording to a channel access priority class (p).

TABLE 6 Channel Access Priority Class (p) m_(p) CW_(min,p) CW_(max,p)T_(ulmcot,p) allowed CW_(p) sizes 1 2  3   7  2 ms {3, 7} 2 2  7  15  4ms {7, 15} 3 3 15 1023  6 ms or {15, 31, 63, 127, 10 ms 255, 511, 1023}4 7 15 1023  6 ms or {15, 31, 63, 127, 10 ms 255, 511, 1023}

A CW size (CWS) applied to a Type 1 CAP may be determined based onvarious methods. As an example, a CWS may be adjusted based on whetherto toggle a New Data Indicator (NDI) value for at least one HARQprocessor related to HARQ_ID_ref, which is a HARQ process ID of a UL-SCHwithin a predetermined time duration (e.g., reference TU).

When a UE performs signal transmission using a Type 1 CAP related to achannel access priority class p on a carrier, if an NDI value for atleast one HARQ process related to HARQ_ID_ref is toggled, the UE setsCW_(p)=CW_(min,p) in all priority classes p∈{1,2,3,4}, and if not, theUE increases CW_(p) to the next higher allowed value in all priorityclasses p∈{1,2,3,4}.

The reference subframe n_(ref) (or reference slot n_(ref)) is determinedas follows.

When a UE receives a UL grant in a subframe (or slot) n_(g) and performstransmission including a UL-SCH without a gap starting from a subframe(or slot) no in subframes (or slots) n₀, n₁, . . . , n_(w), a referencesubframe (or slot) n_(ref) is a subframe (or slot) n₀.

(2) Type 2 Uplink CAP Method

If it is sensed that a channel is idle for at least a sensing periodT_(short_ul)=25 us, a UE may perform uplink transmission (e.g., PUSCH)in an unlicensed band immediately after the sensing is terminated.T_(short_ul) may include T_(sl) (=9 us)+T_(f) (=16 us).

Embodiment: HARQ-ACK Feedback in U-Band

In order to support stand-alone operation in a U-band, for DL data(e.g., PDSCH) reception, HARQ-ACK feedback operation based on U-bandPUCCH/PUSCH transmission of a UE may be essential (Hereinafter, HARQ-ACKis referred to as A/N for convenience). A PUCCH/PUSCH indicates a PUCCHor a PUSCH. For example, a process in which a base station schedules DLdata transmission to a UE through a channel occupancy time (COT)duration secured by performing an LBT (CCA) operation and the basestation indicates to transmit HARQ-ACK feedback for the corresponding DLdata reception from the corresponding UE through the same COT durationmay be considered (hereinafter, an LBT or a CCA is referred to as an LBTfor convenience). As another example, due to a UE processing timeinvolved in decoding of a DL data signal and encoding of a correspondingHARQ-ACK signal, for a reception of scheduled/transmitted DL datathrough a specific COT duration, a process of indicating to transmitHARQ-ACK feedback through another COT duration after the correspondingCOT duration may be considered.

Hereinafter, in the present disclosure, a HARQ-ACK feedback(hereinafter, A/N) configuration/transmission method in a U-band isproposed. Here, the A/N configuration/transmission method may beperformed in consideration of an LBT operation, a COT configuration,etc. The methods proposed in the present disclosure are not limited tothe HARQ-ACK feedback transmission method through a PUCCH/PUSCH, and maybe similarly applied to other UCI (e.g., CSI, SR) transmission methodsthrough a PUCCH/PUSCH. In addition, the methods proposed in the presentdisclosure are not limited to LBT-based U-band operation, and may besimilarly applied to L-band (or U-band) operation not accompanied byLBT. In addition, in the following description, a plurality of CCs(indexes) are replaced with a plurality of BWPs (indexes) configured inone (or more) CC/(serving) cells, or a plurality of CCs/(serving) cellsincluding a plurality of BWPs (that is, a combination of CC (index) andBWP (index)).

First, terms are defined as follows.

-   -   UCI: means control information transmitted by a UE in UL. UCI        includes several types of control information (i.e., UCI type).        For example, UCI includes HARQ-ACK, SR, and CSI.    -   HARQ-ACK: indicates whether DL data (e.g., transport block (TB),        codeword (CW)) on a PDSCH has been successfully received. 1 bit        of HARQ-ACK may be transmitted in response to single DL data,        and 2 bits of HARQ-ACK may be transmitted in response to two DL        data. A HARQ-ACK response/result includes a positive ACK (ACK),        a negative ACK (NACK), a DTX or a NACK/DTX. Here, a HARQ-ACK is        equivalent to am ACK/NACK, an A/N, and an AN.    -   HARQ process number/ID: indicates the number or identifier of a        HARQ process. A HARQ process manages state variables related to        the number of transmissions of a MAC PDU in a buffer, HARQ        feedback for a MAC PDU in a buffer, and a current redundancy        version, etc.    -   PUCCH: means a physical layer UL channel for UCI transmission.        For convenience, for A/N, SR, and CSI transmission, PUCCH        resources configured and/or indicated for transmission by a base        station are referred to as a A/N PUCCH resource, a SR PUCCH        resource, and a CSI PUCCH resource, respectively.    -   PUSCH: means a physical layer UL channel for UL data        transmission.    -   Slot: means a basic time unit (TU) (or time interval) for data        scheduling. A slot includes a plurality of symbols. Here, a        symbol includes an OFDM-based symbol (e.g., a CP-OFDM symbol, a        DFT-s-OFDM symbol). In the present disclosure, a symbol, an        OFDM-based symbol, an OFDM symbol, a CP-OFDM symbol, and a        DFT-s-OFDM symbol may be substituted for each other.

Each of the proposed methods described below may be combined and appliedtogether as long as they do not contradict each other.

(1) Basic Operation Method

Basic operation methods for the A/N feedback configuration/transmissionmethod proposed in the present disclosure will be described as follows.In the present disclosure, A/N triggering DCI includes at least DL grantDCI, and (in addition to the DL grant DCI) may further include UL grantDCI and/or specific DCI that does not schedule PDSCH/PUSCH transmission.

1) Timing-Based A/N Feedback Method (Hereinafter, t-A/N Method) (FIGS.12A and 12B)

A. After configuring a plurality of candidate HARQ timings through RRCsignaling in advance, a base station may indicate to a UE one of theplurality of candidate HARQ timings through (DL grant) DCI. In thiscase, a UE may operate to transmit A/N feedback for (a plurality of)PDSCH reception through indicated the HARQ timing in a plurality ofslots (or a slot set; for convenience, a bundling window) correspondingto an entire candidate HARQ timing set. Here, A HARQ timing means aPDSCH-to-A/N timing/interval. A HARQ timing may be expressed in units ofslots.

For example, when A/N transmission is indicated in a slot #m, A/Ninformation may include response information for PDSCH reception in aslot #(m−i). Here, a slot #(m−i) corresponds to a slot corresponding tocandidate HARQ timings. FIG. 12A illustrates a case where candidate HARQtimings are configured to i={2, 3, 4, 5}. In this case, when the A/Ntransmission time is indicated as #(n+5)(=m), a UE may generate andtransmit A/N information for PDSCH reception of slots #n˜#(n+3)(=m−i)(i.e., A/N feedback for all 4 slots). Here, A/N responses to PDSCHreception of slots #n+1/#n+3 may be treated as NACKs.

For convenience, this A/N feedback configuration/transmission method isreferred to as “Type-1 A/N codebook”.

B. In addition to a HARQ timing indication, a counter DownlinkAssignment Index (c-DAI) and/or a total-DAI (t-DAI) may be signaledtogether through (DL grant) DCI. A c-DAI may inform in which order aPDSCH corresponding to (DL grant) DCI is scheduled. A t-DAI may informof the total number of PDSCHs (or the total number of slots in whichPDSCHs exist) scheduled up to the present (slot). Accordingly, a UE mayoperate to transmit A/N for PDSCHs corresponding to a c-DAI values froman initial c-DAI value to (received) last t-DAI value through anindicated HARQ timing. When the number of serving cells configured for aUE is one, a c-DAI and a t-DAI may have the same meaning. Accordingly, at-DAI may be included in (DL grant) DCI only when the number of servingcells is plural. When a plurality of serving cells are configured in aUE, a c-DAI is first counted in the cell-domain, and then the c-DAI mayinform of a scheduling order of a PDSCH counted in a time-domain (or anorder (of a serving cell, a slot) in which a PDSCH exists). Similarly, at-DAI may inform of the total number of PDSCHs scheduled up to thepresent (slot) (or the total number of serving cells, slots in whichPDSCHs exist). Here, a c-DAI/t-DAI may be defined based on a PDCCH. Inthis case, in the above description, the PDSCH may be replaced with aPDCCH, and the slot in which the PDCCH exists may be replaced with aPDCCH monitoring opportunity in which a PDCCH (or DCI) related to thePDCCH exists.

Each c-DAI/t-DAI may be indicated using a 2-bit value. A number greaterthan 4 can be indicated as follows using a modulo operation.

-   -   When a DAI bit is 00 (e.g., DAI value=1): indicates 4n+1 (i.e.,        1, 5, 9, . . . )    -   When a DAI bit is 01 (e.g., DAI value=2): indicates 4n+2 (i.e.,        2, 6, 10, . . . )    -   When a DAI bit is 10 (e.g., DAI value=3): indicates 4n+3 (i.e.,        3, 7, 11, . . . )    -   When a DAI bit is 11 (e.g., DAI value=4): indicates 4n+4 (i.e.,        4, 8, 12, . . . )    -   n represents an integer greater than or equal to 0.

FIG. 12B illustrates a case in which a DAI is signaled through (DLgrant) DCI in the same situation as FIG. 12A. Referring to FIG. 12B, aPDSCH scheduled by DCI having DAI=00 in a slot #n may be received, and aPDSCH scheduled by DCI having DAI=10 in a slot #(n+2) may be received.In this case, a UE may generate/transmit A/N information only forreception of three PDSCHs corresponding to consecutive DAI values (i.e.,DAI=00/01/11) (hereinafter, a DAI sequence). Here, an A/N response forreception of a PDSCH corresponding to DAI=01 may be processed as a NACK.

2) Pooling-Based A/N Feedback Method (Hereinafter, p-A/N Method) (FIG.13 )

A. An operation of delaying (pending/deferring) A/N feedbacktransmission for a corresponding PDSCH may be indicated through DL grantDCI. Thereafter, through DCI, transmission of A/N feedback for PDSCH(s)corresponding to (i) all DL HARQ process IDs, or (ii) specific partialDL HARQ process ID(s) may be indicated (pooling). A/N feedback may betransmitted through a timing configured/indicated based on a specificsignal (e.g., RRC or DCI signaling). A/N pooling may be indicatedthrough a DL grant (e.g., DCI format 1_0/1_1), a UL grant (e.g., DCIformat 0_0/0_1) or other DCI (e.g., UE (group) common DCI). Forconvenience, DCI indicating A/N pooling is referred to as pooling DCI. AHARQ process ID to be pooled may be preconfigured/predefined or may beindicated through pooling DCI. A/N pooling may be indicated in units ofwhole/group/individual HARQ process IDs.

For example, referring to FIG. 13 , a UE may receive three PDSCHs from abase station, and HARQ process IDs (HpIDs) assigned to each PDSCH may be0, 3, and 2. In addition, A/N pending (AN=pe) may be indicated for threePDSCHs through each DL grant DCI. In this case, a UE delays A/Ntransmission for PDSCHs reception corresponding to HpID=0/3/2.Thereafter, upon receiving a pooling DCI (AN=pooling) from a basestation, a UE may transmit A/N for PDSCHs reception corresponding to allor some HpIDs at a time.

B. When c-/t-DAI signaling is configured in t-A/N method (e.g., when aDAI is signaled through DL grant DCI), A/N pooling corresponds to a HARQprocess ID (indicated through pooling DCI) may be defined as pulling A/Ntransmission for a PDSCH corresponding to a HARQ process ID or pullingA/N transmission for a PDSCH corresponding to a t-DAI value (indicatedthrough pooling DCI). In the latter case, a UE may transmit A/Ninformation for PDSCHs reception corresponding to a c-DAI initial valueto a t-DAI value at a time.

(2) Proposed Method 1

In the case of proposed method 1, through A/N triggering DCI, 1)timing-A indicating an actual A/N transmission timing, and 2) timing-Dindicating a reference A/N timing corresponding to a (DL PDSCH) slotgroup that is an A/N feedback target may be signaled.

Based on this, a UE may operate to transmit A/N feedback for a slotgroup (PDSCH reception through the slot group) corresponding to timing-Dthrough the time indicated by timing-A. In this case, a A/N payload maybe mapped (e.g., ordered) in a slot index order belonging to acorresponding slot group.

For example, A/N triggering DCI (or, if A/N triggering DCI is a DL grantDCI, a corresponding PDSCH) is transmitted/detected through a slot #n,and timing-A=K and timing-D=L through a corresponding DCI may beindicated. In this case, a UE may operate to transmit A/N feedback for aslot group (i.e., PDSCH reception through the slot group) correspondingto a slot #(n+K−L) through a slot #(n+K). Here, a slot group may bedefined as a timing set including a plurality (e.g., M) of candidatetiming values D_m (m=0, 1, . . . , M−1). For example, a slot groupcorresponding to a slot #n may be configured/defined as M slotscorresponding to slots #(n−D_m) or slots #(n+D_m) (m=0, 1, . . . , M−1).In this case, a slot group corresponding to a slot #(n+K−L) may beconfigured/defined as slots #(n+K−L−Dm) or slots #(n+K−L+D_m) (m=0, 1, .. . , M−1).

On the other hand, a timing set defining a slot group may be configuredto be the same as a set of candidate timing-A values (e.g., K_m; m=0, 1,. . . , M−1) that can be indicated by timing-A, or may be configuredindependently (differently). For example, a bundling windowcorresponding to a slot #n may be configured as slots #(n−K_m), and aslot group corresponding to a slot #n may be also defined by a timingset configured with K_m (m=0, 1, . . . , M−1). For example, A/Ntriggering DCI (or, when A/N triggering DCI is DL grant DCI, acorresponding PDSCH) may be transmitted/detected through a slot #n, andtiming-A=K and timing-D=L may be indicated through the correspondingDCI. In this case, a UE may operate to transmit A/N feedback for a slotgroup (PDSCH reception through the slot group) corresponding to a slot#(n+K−L) through a slot #(n+K). Here, a slot group corresponding to aslot #(n+K−L) may be configured with slots #(n+K−(K_m+L)) (m=0, 1, . . ., M−1).

On the other hand, when A/N triggering DCI is the same as DL grant DCI(that is, both timing-A and timing-D are signaled through DL grant DCI),a UE may operate to transmit (at the same time, for example, through onePUCCH/PUSCH) by combining 1) A/N feedback for a bundling window (PDSCHreception through the bundling window) corresponding to timing-A and 2)A/N feedback for a slot group (PDSCH reception through the slot group)corresponding to timing-D, through the time indicated by timing-A.

For example, when DL grant DCI or a corresponding PDSCH istransmitted/detected through a slot #n and timing-A=K and timing-D=L areindicated through a corresponding DCI, a UE may operate to transmit bycombining 1) A/N feedback for a bundling window (PDSCH reception throughthe bundling window) corresponding to a slot #(n+K) and 2) A/N feedbackfor a slot group (PDSCH reception through the slot group) correspondingto a slot #(n+K−L), through a slot #(n+K). Here, a slot groupcorresponding to a slot #(n+K−L) may be configured/defined as (i) slots#(n+K−L−Dm) or slots #(n+K−L+D_m) (m=0, 1, . . . , M−1), or (ii) slots#(n+K−(K_m+L)) (m=0, 1, . . . , M−1).

Additionally, (e.g., when A/N triggering DCI is the same as DL grantDCI) it may be indicated through DCI that there is no timing-D and/or aslot group corresponding thereto (A/N feedback request for this). Forexample, when timing-D=a specific value (e.g., 0) is configured, it mayindicate that there is no corresponding slot group (A/N feedback requestfor this).

Additionally, (e.g., when A/N triggering DCI is the same as DL grantDCI) it may be indicated through DCI (e.g., through a timing-Dindication field) that A/N feedback is transmitted only for a specificpart (e.g., first or last slot) among slots belonging to a bundlingwindow (or a slot group corresponding to timing-D) corresponding totiming-A.

As another method, a method of signaling A/N feedback transmissiontriggering for timing-A/timing-D and a corresponding slot group (e.g.,bundling window) corresponding thereto, through UE (group)-common DCImay also be considered.

Meanwhile, due to a limited DCI field size/number of bits, a referenceA/N timing (corresponding A/N feedback target slot group) that can beindicated by timing-D may be limited. In consideration of this, it maybe indicated that A/N feedback for PDSCH reception corresponding to all(not a specific slot group) or some (pre-specified) specific HARQprocess IDs is transmitted, through a specific state of a timing-Dindication field.

Meanwhile, A/N transmission PUCCH/PUSCH resources (sets) may beconfigured differently for each timing-D value. For example, A/Ntransmission PUCCH/PUSCH resources (sets) may be configured differentlyfor each slot group corresponding to each timing-D value. In addition, acorresponding timing-D value (for example, corresponding to a A/Nfeedback target slot group to a corresponding PUCCH/PUSCH resource(set)) for each A/N transmission PUCCH/PUSCH resource (set) may beconfigured differently. For example, a slot group corresponding to eachPUCCH/PUSCH resource (set) may be configured differently, andaccordingly, a timing-D value may be configured differently.

(3) Proposed Method 2

In the case of proposed method 2, in a situation where one slot groupsize (e.g., the number N of slots in a single slot group or the maximumnumber N of schedulable PDSCHs in a single slot group) is preconfiguredin advance, 1) a current-ID (c-ID) indicating a slot group ID to which aslot in which a corresponding DCI or a corresponding PDSCH istransmitted belongs may be signaled through DL grant DCI, and 2) afeedback-ID (f-ID) indicating a slot group ID to be an A/N feedbacktarget (DL PDSCH) may be signaled through A/N triggering DCI.

Based on this, a UE may transmit A/N feedback for a slot group (PDSCHreception through the slot group) corresponding to a feedback-ID throughthe time (e.g., slot) indicated as a A/N transmission timing. Here, aslot group corresponding to a feedback-ID includes a slot in which acurrent-ID of the same value as a previous feedback-ID issignaled/received, that is, a slot in which a current-ID having the samevalue as a feedback-ID is signaled/received through DL grant DCI.

Here, for an A/N payload for a slot group corresponding to a feedback-ID(in a situation where a counter-DAI is configured to be signaled throughDL grant DCI), it may be mapped (ordered) in an order of counter-DAIvalues (e.g., from 1 to N) received through DL grant DCI.

For example, referring to FIG. 14 , A/N triggering DCI (or, when A/Ntriggering DCI is DL grant DCI, a corresponding PDSCH) may betransmitted/detected through a slot #n, timing-A (T-A)=K and feedback-ID(f-ID)=X may be indicated through a corresponding DCI. In this case, aUE may transmit A/N feedback for PDSCH reception in a slot group (i.e.received as current-ID (c-ID)=X through DL grant DCI) corresponding toslot group ID=X in a slot #(n+K).

Meanwhile, a counter-DAI may be determined/signaled to have a continuousvalue (starting from an initial value (e.g., 1)) in one slot group (ID)as shown in FIG. 12B. That is, a counter-DAI value may be independentlydetermined/signaled between different slot groups. In addition, a slotgroup (indicated through DCI) may be defined in a form of a DAI sequenceincluding counter-DAI values from 1 to N corresponding to the same slotgroup ID value. In this case, a slot group may be configured asdiscontinuous slots based on a received/detected counter-DAI. In thepresent disclosure, a slot group ID and a DAI sequence ID may bereplaced/compatible with each other.

On the other hand, when A/N triggering DCI is the same as DL grant DCI(that is, both a current-ID and a feedback-ID are signaled through DLgrant DCI), a UE may operate to transmit (simultaneously, for example,through one PUCCH/PUSCH) by combining (e.g., concatenate) 1) A/Nfeedback for a bundling window corresponding to timing-A or a slot group(PDSCH reception through the slot group) corresponding to a current-IDand 2) A/N feedback for a slot group (PDSCH reception through the slotgroup) corresponding to a feedback-ID, through the time indicated bytiming-A.

Meanwhile, in the present disclosure, that a feedback-ID issignaled/indicated through A/N triggering DCI (e.g., DL grant DCI, ULgrant DCI) may mean that a total-ID indicating the total number of(PDSCH) slot groups (IDs) targeted for A/N feedback transmission/requestis signaled through a corresponding DCI, and a specific slot group IDdetermined from a total-ID and a current-ID is applied as a feedback-ID.For example, in a situation where up to two (PDSCH) slot group IDs(e.g., ID=0 or ID=1) are set/configured, when a current-ID is indicatedas X and a total-ID is indicated as 1, a feedback-ID may bedetermined/applied to X (which is the same value as a current-ID). Asanother example, in a situation where up to two (PDSCH) slot group IDs(e.g., ID=0 or ID=1) are set/configured, a current-ID is indicated as Xand a total-ID is indicated as 2, a feedback-ID may bedetermined/applied to Y (which is a different value from a current-ID).In this case, X and Y may be determined to be different values (e.g.,Y=1 if X=0, or Y=0 if X=1). This method of determining a feedback-ID isreferred to as “Method 1” for convenience.

For example, DL grant DCI or a corresponding PDSCH istransmitted/detected through a slot #n, and timing-A=K, current-ID=X,and feedback-ID=Y (or total-ID=2) may be indicated. In this case, a UEmay transmit by combining 1) A/N feedback for a bundling windowcorresponding to a slot #(n+K) or a slot group (PDSCH reception throughthe slot group) corresponding to ID=X and 2) A/N feedback for a slotgroup (PDSCH reception through the slot group) corresponding to ID=Y,through a slot #(n+K).

On the other hand, in the present disclosure, a total-DAI and/or a NFI(New Feedback Indicator) for a feedback-ID (corresponding (PDSCH) slotgroup thereto) signaled/indicated through A/N triggering DCI (e.g., DLgrant DCI, UL grant DCI) may means a total-DAI and/or a NFI for afeedback-ID determined according to Method 1, or a total-DAI and/or aNFI for an other-ID (a slot group corresponding thereto) having a valuedifferent from a current-ID (regardless of a value indicated as atotal-ID). As an example of the latter, in a situation where up to two(PDSCH) slot group IDs (e.g., ID=0 or ID=1) are set/configured, whencurrent-ID=X is indicated, “total-DAI and/or NFI for feedback-ID” maymean a total-DAI and/or a NFI for a slot group corresponding toother-ID=Y In this case, X and Y may be determined to be differentvalues (e.g., Y=1 if X=0, or Y=0 if X=1). This method of determining another-ID and applying total-DAI/NFI is referred to as “Method 2” forconvenience.

Here, a NFI is 1-bit information, for A/N feedback (hereinafter,previous A/N feedback) transmitted at the previous (e.g., recent) time,(a) whether a base station has properly detected/received it, (b)whether a base station has failed to detect/receive it may be signaled.In the case of (a), a UE may process the remaining parts except for A/Ncorresponding to a PDSCH scheduled after previous A/N transmission asNACK or DTX (feedback configuration/transmission omitted) toconfigure/transmit the updated A/N feedback. In the case of (b), a UEmay configure/transmit A/N feedback by maintaining the remaining partsexcept for A/N corresponding to a PDSCH scheduled after previous A/Ntransmission. In case of (a), an NFI value toggled from an NFI valuereceived through previous DCI is indicated through current DCI. In case(b), an NFI value that is not toggled from an NFI value received throughprevious DCI may be indicated through current DCI.

For example, DL grant DCI or a corresponding PDSCH istransmitted/detected through a slot #n, and timing-A=K, current-ID=X andfeedback-ID=Y (or, total-ID value=2) respectively indicated through acorresponding DCI, a UE may operate to transmit by combining 1) A/Nfeedback for a bundling window corresponding to a slot #(n+K) or a slotgroup (PDSCH reception through the slot group) corresponding to ID=X and2) A/N feedback for a slot group (PDSCH reception through the slotgroup) corresponding to ID=Y, through a slot #(n+K).

Additionally, (e.g., when A/N triggering DCI is the same as DL grantDCI) it may be indicated (through a feedback-ID (or a total-ID)indication field) through DCI that there is no feedback-ID (or other-ID)and/or slot group (A/N feedback request on the slot group) correspondingthereto. For example, when a feedback-ID is indicated with the samevalue as a current-ID (or a total-ID value is 1), a UE may operate toconfigure/transmit A/N feedback only for (one) slot group correspondingto the current-ID.

Additionally, (e.g., when A/N triggering DCI is the same as DL grantDCI) A/N feedback is transmitted only for a specific part (e.g., thefirst or last slot) among slots belonging to a bundling windowcorresponding to a timing-A or a slot group (or a slot groupcorresponding to a feedback-ID (or an other-ID)) corresponding to acurrent-ID may be indicated through DCI (e.g., through a feedback-ID (ortotal-ID) indication field).

As another method, a method of signaling a current-ID through UE(group)-common DCI #1 and/or signaling A/N feedback transmissiontriggering for a feedback-ID and a slot group corresponding theretothrough a UE (group)-common DCI #2 may be considered. In this case, UE(group)-common DCI #1 and #2 may be separate DCIs or may be configuredas the same DCI.

In another method, a total-DAI is signaled through A/N triggering DCI, aUE may operate to configure/transmit A/N feedback only for counter-DAIvalue(s) from (1 to) to a total-DAI value for a slot group (or abundling window corresponding to a timing-A or a slot groupcorresponding to a current-ID) corresponding to a feedback-ID. That is,A/N feedback may be configured/transmitted only for slot(s) (PDSCHsscheduled through this) corresponding to counter-DAI value(s) from 1 toa total-DAI value. Alternatively, total-DAIs for a slot groupcorresponding to a feedback-ID (or an other-ID) and for a slot groupcorresponding to a current-ID (or a bundling window corresponding to atiming-A) may be signaled through DCI, respectively. In this case, a UEmay operate to configure/transmit A/N feedback based on a total-DAI foreach slot group.

As an example, A/N feedback configuration related information indicatedthrough DL grant DCI may include (i) a current-ID, (ii) acounter/total-DAI for a slot group corresponding to a current-ID (PDSCHsscheduled through this), and (iii) a feedback-ID (or a total-ID). Inaddition, a total-DAI for a slot group (PDSCHs scheduled through this)corresponding to a feedback-ID (or an other-ID) may be further includedin DL grant DCI (i.e., A/N feedback configuration related information).

On the other hand, (i) a current-ID, (ii) a total-DAI for a slot group(PDSCHs scheduled through this) corresponding to a current-ID, (iii) afeedback-ID (or a total-ID), (iv) a total-DAI for a slot groupcorresponding to the feedback-ID (or an other-ID) may be indicatedthrough UL grant DCI. Here, a current-ID and a feedback-ID may bedefined/generalized as two feedback-IDs #1 and #2. Accordingly, a UE mayoperate to transmit A/N feedback for a slot group corresponding tofeedback-IDs #1 and #2 through (PUCCH or) PUSCH (e.g., in a form of UCIpiggyback).

Alternatively, a current-ID (and/or a feedback-ID (or a total-ID)) maynot be included in UL grant DCI. That is, signaling through UL grant DCImay be omitted for a current-ID (and/or a feedback-ID (or a total-ID)).In this case, a UE may operate to configure/transmit A/N feedback (onPUSCH) based on current-ID (and/or feedback-ID (or total-ID))information received through DL grant DCI. Additionally, it may beindicated through a specific field that there is no A/N feedbacktransmission request (e.g., a slot group targeted for A/N feedback)through UL grant DCI. Here, a specific field may include, for example, afeedback-ID (or a total-ID) and/or a current-ID (and/or a feedback-ID(or an other-ID) and/or a total-DAI corresponding to a current-ID)indication fields.

As another method, a current-ID and a starting-ID may be indicatedthrough A/N triggering DCI (e.g., DL grant DCI, UL grant DCI). In thiscase, a UE may operate to configure/transmit A/N feedback for a slotgroup set A (PDSCH reception through it) corresponding to (plural)consecutive slot group ID(s) from a starting-ID to a current-ID. When astarting-ID is indicated with the same value as a current-ID, a UE mayoperate to configure/transmit A/N feedback only for (one) slot groupcorresponding to a current-ID. Here, a current-ID may bedefined/generalized as an ending-ID.

As an example, A/N feedback configuration related information indicatedthrough DL grant DCI may include at least (i) a current-ID, (ii) a slotgroup (PDSCHs scheduled through this) corresponding to a current-ID,(iii) a starting-ID. In addition, a (single) total-DAI commonly appliedto each (plural) slot group(s) belonging to a slot group set A(excluding a slot group corresponding to a current-ID) may be furtherincluded in DL grant DCI (i.e., A/N Feedback configuration relatedinformation).

As another example, through UL grant DCI, (i) a current-ID, (ii) atotal-DAI for a slot group (PDSCHs scheduled through this) correspondingto a current-ID, (iii) a starting-ID, (iv) a (single) total-DAI commonlyapplied to each (plural) slot group(s) belonging to a slot group set A(excluding a slot group corresponding to a current-ID) may be indicated.Accordingly, a UE may operate to transmit A/N feedback for a slot groupset corresponding to a starting-ID to a current-ID through (PUCCH or)PUSCH (e.g., in a form of UCI piggyback).

As another example, a current-ID (and/or a starting-ID) may not beincluded in UL grant DCI. That is, signaling for a current-ID (and/or astarting-ID) through UL grant DCI may be omitted. In this case, a UE mayoperate to configure/transmit A/N feedback (on PUSCH) based oncurrent-ID (and/or starting-ID) information received through DL grantDCI. Additionally, it may be indicated through a specific field thatthere is no A/N feedback transmission request (e.g., a slot grouptargeted for A/N feedback) through UL grant DCI. Here, a specific fieldmay include, for example, a starting-ID and/or a current-ID (and/or acorresponding total-DAI) indication fields.

On the other hand, when the above-described method or other methods areapplied, the number of simultaneously transmitted (single) A/N feedbackconfiguration target slot groups may be dynamically changed (e.g., 2including a current-ID, or 3 or more including a current-ID). In thiscase, through A/N triggering DCI (e.g., DL grant DCI) and/or UL grantDCI, a (single) total-DAI that is commonly applied to each of aplurality of slot groups (excluding a slot group corresponding to acurrent-ID) targeted for A/N feedback configuration may be indicated.

On the other hand, due to a limited DCI field size/number of bits, theremay be a limit to a slot group ID (corresponding A/N feedback targetslot group) that can be indicated by a current-ID/feedback-ID (ortotal-ID). In consideration of this, through a specific state of acurrent-ID/feedback-ID (or total-ID) indication field, it is indicatedto transmit A/N feedback for PDSCH reception corresponding to all (not aspecific slot group) or some (pre-specified) specific HARQ process IDs.

On the other hand, for each slot group ID value (for a slot groupcorresponding to a corresponding ID), a A/N transmission PUCCH/PUSCHresource (set) may be configured differently, or a slot group ID valuecorresponding to each A/N transmission PUCCH/PUSCH resource (set) (e.g.,A/N feedback target to a corresponding PUCCH/PUSCH resource (set)) maybe configured differently. For example, with respect to A/N feedback forslot group ID=X, a UE may operate to transmit by selecting/using aPUCCH/PUSCH resource (set) configured in slot group ID=X.

Additionally, in a situation in which a plurality of carriers areaggregated/configured to one UE (i.e., CA situation), for a slot groupID, Opt 1-1) the same slot group ID may be indicated/specified in commonfor all multiple carriers at the same time (e.g., slot timing) or timeduration, or Opt 1-2) a slot group ID may be individuallyindicated/specified for each carrier in an order of frequency(carrier)-first time (slot group)-second (second).

Additionally, in a situation where a slot group ID isindicated/specified in a CA situation, for a counter-DAI, 1) (in asituation in which Opt 1-1 is applied) a PDSCH scheduling counter valuemay be determined/indicated in an order of frequency (carrier)-firsttime (slot)-second in one slot group (ID), or 2) (in a situation inwhich Opt 1-2 is applied) a PDSCH scheduling counter value may beindependently determined/indicated in one slot group (ID) for eachcarrier.

(4) Proposed Method 3

Prior to the description of the proposed method, A/N feedbackconfiguration/transmission and related basic operation methods will bedescribed as follows. The tA/N method and the pA/N method aresubstantially the same as those described with reference to FIGS. 12A-13, and are described again below to classify the A/N feedbackconfiguration/transmission methods (or A/N codebook method).

1) Timing-Based A/N Feedback Method (t-A/N Method)

A. After configuring a plurality of candidate HARQ timings through RRCsignaling in advance, a base station may indicate to a UE one of aplurality of candidate HARQ timings through (DL grant) DCI. In thiscase, a UE may operate to transmit A/N feedback for (plural) PDSCHreception in a plurality of slots (or a slot set; a bundling window)corresponding to an entire candidate HARQ timing set through anindicated HARQ timing. Here, HARQ timing means PDSCH-to-A/Ntiming/interval. HARQ timing may be expressed in units of slots.Hereinafter, the above-described method is referred to as a Type-1 A/Ncodebook.

B. In addition to a HARQ timing indication, a counter DownlinkAssignment Index (c-DAI) and/or a total-DAI (t-DAI) may be signaledtogether through (DL grant) DCI. A c-DAI may inform in which order aPDSCH corresponding to (DL grant) DCI is scheduled. A t-DAI may informof the total number of PDSCHs (or the total number of slots in whichPDSCHs exist) scheduled up to the present (slot). Accordingly, a UE mayoperate to transmit A/N for PDSCHs corresponding to a c-DAI values froman initial c-DAI value to (received) last t-DAI value through anindicated HARQ timing. Hereinafter, the above-described method isreferred to as a Type-2 A/N codebook.

C. PDSCH (slot) group ID-based A/N feedback method (hereinafter, Type-2aA/N codebook)

i. A Current-ID may be signaled through DL grant DCI, and a feedback-IDmay be signaled through A/N triggering DCI. Here, a current-ID is usedto indicate a slot group ID to which a slot in which DL grant DCI or acorresponding PDSCH is transmitted belongs. In addition, a feedback-IDis used to indicate a (DL PDSCH) slot group ID to be a target of A/Nfeedback. Here, a total-ID is signaled through DCI, and a feedback-IDcan be inferred from a total-ID based on the Method 1.

ii. A UE may transmit A/N feedback for a slot group (PDSCH receptionthrough the slot group) corresponding to a feedback-ID through the timeindicated by an A/N transmission timing.

iii. When A/N triggering DCI is the same as the DL grant DCI (i.e., botha current-ID and a feedback-ID (or a total-ID) are signaled through DLgrant DCI), a UE may operate to transmit by combining (at the same time,for example, through one PUCCH/PUSCH) 1) A/N feedback for a bundlingwindow corresponding to a timing-A or a slot group (PDSCH receptionthrough the slot group) corresponding to a current-ID and 2) A/Nfeedback for a slot group (PDSCH reception through the slot group)corresponding to a feedback-ID, through the time indicated by atiming-A.

2) Pooling-Based A/N Feedback Method (p-A/N Method)

A. An operation of delaying (pending/deferring) A/N feedbacktransmission for a corresponding PDSCH may be indicated through DL grantDCI. Thereafter, through DCI, transmission of A/N feedback for PDSCH(s)corresponding to (i) all DL HARQ process IDs or (ii) specific partial DLHARQ process ID(s) may be indicated (pooling). A/N feedback may betransmitted through timing configured/indicated based on a specificsignal (e.g., RRC or DCI signaling). Hereinafter, the above-describedmethod is referred to as a Type-3 A/N codebook.

B. When c-/t-DAI signaling is configured in the t-A/N method (e.g., whena DAI is signaled through DL grant DCI), A/N pooling may be defined aspooling A/N transmission for a PDSCH corresponding to a HARQ process ID(indicated through pooling DCI), or pooling A/N transmission for a PDSCHcorresponding to a t-DAI value (indicated through pooling DCI). In thelatter case, a UE may transmit A/N information for PDSCH receptioncorresponding to a c-DAI initial value to a t-DAI value at a time.

3) Dynamic Switching Operation Method Between the t-A/N Method and thep-A/N Method

A. As an example, switching between the t-A/N method and the p-A/Nmethod may be indicated through DL grant DCI. That is, it may beindicated whether to configure/transmit A/N feedback by applying eitherthe t-A/N method or the p-A/N method through DL grant DCI. Additionally,both A/N pending and A/N pooling for the p-A/N method may be indicatedthrough the same DL grant DCI. For example, when DL grant DCI indicatesthe p-A/N method, the DL grant DCI may further indicate whether toindicate pending A/N feedback transmission or pooling.

B. As another example, switching between A/N pending operations forapplying the t-A/N method and the p-A/N method may be indicated throughDL grant DCI. That is, it may be indicated whether the t-A/N method isapplied or A/N feedback transmission is pending for the p-A/N methodthrough DL grant DCI. Here, an A/N pooling operation for the p-A/Nmethod may be indicated through UL grant DCI or (UE (group)) common DCI.

C. As another example, switching between the t-A/N method and A/Npending for the p-A/N may be indicated through DL grant DCI includingPDSCH scheduling. That is, it may be indicated whether to apply thet-A/N or to pending A/N transmission for the p-A/N method through DLgrant DCI. In this case, A/N pooling for the p-A/N method may beindicated through DL grant DCI that does not include PDSCH scheduling.

4) NFI (New Feedback Indicator) Information Signaling

A. Due to A/N feedback transmission drop of a UE due to LBT failureand/or A/N feedback detection failure in a base station, etc., for thepurpose of preventing inconsistency in an A/N codebook (payload)configuration between a UE and a base station (and a CWS (ContentionWindow Size) update for an LBT operation accompanying an A/N PUCCH(including UL transmission such as a PUSCH, etc.)), a 1-bit NFI may besignaled through (e.g., DL grant or UL grant) DCI triggering A/Nfeedback transmission. An NFI may indicate the following information ina toggling form.

i. For A/N feedback (hereinafter, previous A/N feedback) transmitted atthe previous (recent) time, whether (a) it was properlydetected/received by a base station, (b) a base station failed todetect/receive it may be signaled. In the case of (a), a UE processesthe remaining parts except for A/N corresponding to a PDSCH scheduledafter previous A/N transmission as NACK or DTX (feedbackconfiguration/transmission omitted) to configure/transmit updated A/Nfeedback. In the case of (b), a UE may configure/transmit A/N feedbackby maintaining the remaining parts except for A/N corresponding to aPDSCH scheduled after previous A/N transmission.

ii. In the case of (a), an NFI value toggled from an NFI value receivedthrough previous DCI is indicated through current DCI. In the case of(b), an NFI value that is not toggled from an NFI value received throughprevious DCI may be indicated through current DCI. When a UE receives atoggled NFI, a UE may operate to reset a CWS for an A/N PUCCH (and/or aPUSCH) transmission to the minimum value, but on the other hand, when aUE receives a non-toggle NFI, a UE may operate to increase a CWS value(in a certain unit).

Hereinafter, a DL/UL grant DCI configuration method and signalinginformation when configuring Type-2a and Type-1 A/N codebooks areproposed. Meanwhile, in this disclosure, DCI (format) in which a fieldconfiguration and each field size, etc. in a DCI format are configurable(that is, changeable) is referred to as a non-fallback DCI, and DCI(format) in which a DCI field configuration and respective sizes are notconfigurable (i.e., fixed) is referred to as fallback DCI. DCI, which isnot separately specified as fallback DCI in this disclosure, may meannon-fallback DCI.

(a) DCI Configuration and Signaling Information when Configuring aType-2a A/N Codebook

1) Information Signaled Through DL Grant DCI

A. Basically, it may include the following information (for convenience,basic information).

i. current-ID information

ii. Counter-DAI and total-DAI information related to a (PDSCH) slotgroup corresponding to a current-ID

iii. feedback-ID information

1. Alternatively, a total-ID may be signaled through DCI, andfeedback-ID information may be determined based on Method 1.

iv. NFI information for A/N feedback corresponding to a current-ID(i.e., NFI for current-ID)

v. NFI information for A/N feedback corresponding to a feedback-ID(i.e., NFI for feedback-ID)

1. Based on Method 2 (regardless of a value indicated by a total-ID), itcan be replaced with NFI information for A/N feedback corresponding toan other-ID having a value different from a current-ID (that is, NFI forother-ID).

B. In addition, it may further include the following information.

i. Total-DAI information related to a (PDSCH) slot group correspondingto a feedback-ID

1. Based on Method 2 (regardless of a value indicated by a total-ID), itcan be replaced with total-DAI information for A/N feedbackcorresponding to an other-ID having a value different from a current-ID(that is, total-DAI for other-ID).

C. In addition, it may further include the following information.

i. Whether to configure/transmit A/N feedback based on a Type-3 codebook(e.g., CTI (Codebook Type Indicator) signaling indicating which A/Ncodebook to configure/transmit among Type-2a and Type-3)

ii. Notes

1. If Type-3 is indicated through DCI (at the specific time), NFIinformation for Type-3 codebook-based A/N feedback (i.e., NFI forType-3) may be additionally signaled through DCI.

2. CTI information may be explicitly signaled using a dedicated 1-bit,or implicitly signaled in the following way.

3. In a first method, when A/N feedback transmission is indicated foronly one (PDSCH) slot group corresponding to a current-ID through DCI,CTI information may be signaled through a NFI for feedback-ID (or NFIfor other-ID) bit/field. When Type-3 is indicated through CTI, through acounter-DAI, a total-DAI bit/field, and/or a NFI for current-IDbit/field, a HARQ process ID group for A/N feedback and/or (in CAsituation) CC/cell group may be indicated and/or NFI for Type-3information may be signaled.

4. In a second method, when A/N feedback transmission is indicated foronly one (PDSCH) slot group corresponding to a current-ID through DCI,CTI information may be signaled through a total-DAI for feedback-ID (ortotal-DAI for other-ID) bit/field. When Type-3 is indicated through CTI,through a counter-DAI, a total-DAI (for current-ID) bit/field, a NFI forcurrent-ID, and/or a NFI for feedback-ID (or NFI for other-ID)bit/field, a HARQ process ID group and/or (in CA situation) CC/cellgroup to be A/N feedback target may be indicated and/or NFI informationfor Type-3 may be signaled.

D. In relation to Fallback DCI-based DL scheduling

i. Basically, a fallback DCI format may include/signal only current-IDinformation and/or counter-DAI information (related to a (PDSCH) slotgroup corresponding to a corresponding ID) among the basic informationdescribed above (for convenience, Case 1).

ii. As another method, all of the basic information except a total-DAIfor current-ID may be included/signaled in a fallback DCI format.

iii. In this case, for information not included/signaled in fallbackDCI, a UE may A/N codebook (payload) based on the most recentlydetected/received information through non-fallback DL DCI (e.g.,feedback-ID (or total-ID), NFI, CTI). Here, non-fallback DL DCI relatedto the recently detected/received information may be limited to only DCIindicating the HARQ-ACK (PUCCH) transmission time (slot) indicatedthrough fallback DL DCI for the HARQ-ACK (PUCCH) transmission time. Ifthere is no non-fallback DCI indicating the same HARQ-ACK (PUCCH)transmission time as fallback DCI, according to Case 1, a UE mayconfigure/transmit A/N feedback only for a slot group corresponding to acurrent-ID, and, for NFI for current-ID, a UE may operate toassume/apply a toggled form (or a non-toggled form) (compared toprevious A/N feedback or compared to previously (i.e., recently)received a NFI bit). In addition, a UE may operate by assuming/applyingthat CTI is indicated by a Type-2a codebook.

iv. Meanwhile, in order to prevent in advance A/N feedback mismatchbetween a UE and a base station due to a UE's DL DCI detection failure,etc., a plurality of fallback DL DCIs indicating the same HARQ-ACK(PUCCH) transmission time (e.g., slot) may be configured to indicate thesame current-ID. Accordingly, a UE may operate by assuming that that allof a plurality of fallback DL DCIs indicating the same HARQ-ACK (PUCCH)transmission time indicate the same current-ID, and if other DCI isdetected, a UE may ignore the DCI (discard). For example, a UE may notperform an operation indicated by the corresponding DCI.

E. In relation to CB group (CBG) based DL transmission operation

i. For a CC/cell in which CBG based DL transmission is configured,total-DAI for feedback-ID (or total-DAI for other-ID) information may beindividually signaled for an A/N sub-codebook corresponding to TB basedtransmission and an A/N sub-codebook corresponding to CBG basedtransmission.

2) Information Signaled Through UL Grant DCI

A. Basically, it may include the following information (for convenience,basic information).

i. Total-DAI information for a first (PDSCH) slot group ID (hereinafter,first-ID)

ii. Total-DAI information for a second (PDSCH) slot group ID(hereinafter, second-ID)

iii. Notes

1. For example, when up to two (PDSCH) slot groups (index=0, 1) aredefined/configured, a first-ID and a second-ID may correspond to slotgroup indexes 0 and 1, respectively.

2. As another example, a first-ID and a second-ID may beconfigured/replaced with a current-ID and a feedback-ID (or other-ID),respectively. In this case, current-ID information and feedback-ID (ortotal-ID) information may be further signaled through DCI.

A. In a case of feedback-ID, a total-ID is signaled through DCI, andfeedback-ID information may be determined based on Method 1.

B. An other-ID may be determined as a slot group ID having a differentvalue from a current-ID based on Method 2.

3. As another example, bitmap information for an entire slot groupID/index set (e.g., ID/index=0, 1) may be signaled through DCI. Whethera slot group corresponding to a corresponding ID is an A/N feedbackrequest/transmission target for each slot group ID may be indicatedthrough a corresponding group ID-bitmap.

4. Meanwhile, UL grant DCI may not include slot group ID/index-relatedinformation/signaling. In this case, a UE may operate toconfigure/transmit an A/N codebook (payload) based on the most recentlydetected/received slot group ID/index information through DL grant DCI.Here, DL grant DCI related to a slot group ID/index may be limited toonly DCI indicating the PUSCH transmission time (slot) scheduled throughUL grant DCI for the HARQ-ACK transmission time.

B. In addition, it may further include the following information.

i. NFI information for A/N feedback corresponding to a first-ID

ii. NFI information for A/N feedback corresponding to a second-ID

iii. Notes

1. In this case, A/N feedback transmission (through PUSCH) may beindicated to a UE without additional DL (PDSCH) scheduling/transmissionfrom a base station.

2. Otherwise, UL grant DCI may not include NFI information for A/Nfeedback. In this case, a UE may operate to configure/transmit an A/Ncodebook (payload) based on the most recently detected/received NFIinformation through DL grant DCI (for each (PDSCH) slot group). Here, DLgrant DCI related to NFI information may be limited to only DCIindicating the PUSCH transmission time (slot) scheduled through UL grantDCI for the HARQ-ACK transmission time for a PDSCH.

In addition, it may further include the following information.

i. Whether to configure/transmit A/N feedback based on a Type-3 codebook(e.g., indicate which A/N codebook to configure/transmit among Type-2aand Type-3)

ii. Notes

1. If Type-3 is indicated through DCI (at the specific time), NFIinformation for Type-3 codebook-based A/N feedback may be additionallysignaled through a corresponding DCI.

D. In relation to Fallback DCI-based UL Scheduling

i. Basically, a fallback DCI format may be a (omitted) form in which allbasic information is not included/signaled.

ii. Alternatively, a fallback DCI format may be a form in which allbasic information (e.g., total-DAI and/or group ID-bitmap informationfor each of a first-ID and a second-ID) is included/signaled.

iii. Alternatively, a fallback DCI format may be a form in which {atotal-DAI for a first-ID, a total-DAI for a second-ID, NFI for afirst-ID, NFI for a second-ID} is included/signaled.

iv. Alternatively, a fallback DCI format may be a form in which {NFI fora first-ID, NFI for a second-ID} (and/or group ID-bitmap information) isincluded/signaled.

v. In this case, with respect to information not included/signaled in ULgrant DCI, a UE may operate to configure/transmit an A/N codebook(payload) based on the most recently detected/received information(e.g., a slot group ID/index, a total-DAI, NFI, a CTI) through DL grantDCI. Here, DL grant DCI related to the recently detected/receivedinformation may be limited to only DCI indicating the PUSCH transmissiontime (slot) scheduled through UL grant DCI for the HARQ-ACK transmissiontime for a PDSCH.

vi. Meanwhile, when an A/N is piggybacked and transmitted through aCG-PUSCH transmitted without DCI in a configured (Configured Grant, CG)form rather than scheduling accompanying dynamic grant DCI transmission,a UE may operate to configure/transmit an A/N codebook (payload) basedon the most recently detected/received information (e.g., a slot groupID/index, a total-DAI, NFI, a CTI) through DL grant DCI. Here, DL grantDCI related to the recently detected/received information may be limitedto only DCI indicating the CG-PUSCH transmission time (slot) for theHARQ-ACK transmission time for a PDSCH.

E. In relation to CB group (CBG) based DL transmission operation

i. For a CC/cell in which CBG based DL transmission is configured,total-DAI (e.g., a total-DAI for a first-ID and a total-DAI for asecond-ID) information may be individually signaled for an A/Nsub-codebook corresponding to TB based transmission and an A/Nsub-codebook corresponding to CBG based transmission.

Meanwhile, when a UE configures/transmits A/N feedback on a PUCCH/PUSCHbased on a Type-2a codebook, a method for a base station toindicate/recognize that “there is no A/N feedback to be piggybacked andtransmitted on a PUSCH” to a UE may be needed. For this, the followingDCI signaling and operation may be considered.

1) Method 1

A. When a total-DAI bit in UL grant DCI is indicated as ‘11’ (or atotal-DAI value is 4) and when there is no DL grant DCI detected duringa bundling window duration (or an interval from the previous (e.g.,recent) A/N feedback transmission time (or the time indicated by thecorresponding transmission time) to a PUSCH transmission timing)corresponding to the PUSCH transmission time and when a NFI bitindicated through UL grant DCI is toggled (compared to the previous A/Nfeedback or compared to the previous (e.g., recent) received NFI bit), aUE may operate not to piggyback any A/N on a PUSCH. This method may beapplied to a method for signaling NFI information through UL grant DCI.Here, a check for DCI information check and a corresponding UE'soperation may be performed independently/individually for each (PDSCH)slot group (ID).

B. In another method, for detected/received UL grant DCI (in the absenceof separate NFI information signaling through UL grant DCI), the checkfor DCI/UE's operation is applied/performed, and a NFI bit may beassumed to be non-toggled (or toggled) (compared to the previous A/Nfeedback or compared to the previous (recently) received NFI bit). Thismethod may be applied to the case of UL grant DCI (format) withoutseparate NFI information signaling (e.g., fallback).

2) Method 2

A. One of states signaled by a total-DAI field in UL grant DCI may bedefined as indicating “no A/N feedback” (to be piggybacked on PUSCH).When a corresponding state is indicated through DCI, a UE may operatenot to piggyback on any A/N on a PUSCH. This method may be applied to amethod without NFI information signaling through UL grant DCI. Here, acheck for DCI information and a corresponding UE's operation may beperformed independently/individually for each (PDSCH) slot group (ID).

3) Method 3

A. Only one (PDSCH) slot group (e.g., first-ID) may be indicated throughfirst-ID and second-ID (or current-ID and feedback-ID (or total-ID))bits/fields in UL grant. In this case, through a specific total-DAIfield (e.g., a total-DAI field for a second-ID), 1) A/N feedback foronly one indicated slot group (e.g., first-ID) (piggyback on a PUSCH))may be indicated to configure/transmit, or 2) it may be indicated thatthere is no A/N feedback to be piggybacked on a PUSCH even for anindicated slot group (e.g., first-ID) (i.e., for all slot groups(first-ID and second-ID)). This method may be applied to a method forsignaling (PDSCH) slot group ID information through UL grant DCI (thereis no NFI information signaling through UL grant DCI). For example, slotgroup ID information includes a first-ID and a second-ID (or current-IDand feedback-ID (or total-ID)) information).

Meanwhile, in the case of scheduling/indicating (multi-slot scheduling)a plurality of PUSCH resources transmitted over a plurality of slotsthrough single UL grant DCI, an operation of applying total-DAI, NFI,and/or CTI information may be required. The corresponding informationmay be applied only to, among a plurality of slots or PUSCH resourcesscheduled through DCI, 1) (a) a PUSCH resource in a first slot (i.e.,first-slot PUSCH), (b) a first PUSCH resource (i.e., first PUSCH), (c)an initial PUSCH resource composed of more than a specific number ofsymbols (or the number of non-DMRS symbols) and/or a specific number ofRBs (or the number of REs or the number of non-DMRS REs), (d) a PUSCHresource allocated in a slot immediately following a first slot in whichPUSCH transmission is indicated, or (e) a first PUSCH resource (i.e.,first full-PUSCH) having the same symbol duration as a slot duration(for example, a specific one resource of the plurality of resources orspecific combinations of resources), alternatively, may be applied onlyto 2) (a) a first successful first-slot PUSCH in LBT (CCA through it),or (b) a first full-PUSCH, alternatively, may be applied only to 3) (a)a first-slot PUSCH in which A/N feedback is transmitted in a piggybackedform, (b) a first PUSCH, or (c) a first full-PUSCH. For the remainingslots or PUSCH resources other than the above, a) an A/N codebook(payload) may be configured/transmitted based on the most recentlydetected/received information (e.g., a slot group ID/index, a total-DAI,NFI, a CTI, and/or information indicating whether to fallback A/N,information indicating the presence or absence of pended A/N to bedescribed later) through DL grant DCI, and/or b) b) a specific (e.g.,default) value may be assumed/applied for the information.

In the of case a), DL grant DCI related to the recentlydetected/received information may be limited to only DCI indicating thePUSCH transmission time (slot) for the HARQ-ACK transmission time for aPDSCH. Meanwhile, in the case of b), it can be assumed/applied asfollows for at least one.

1) For a total-DAI, a total-DAI bit may be assumed/applied as ‘11’ (or atotal-DAI value is 4),

2) it may be assumed/applied to be toggled (or non-toggle) (compared tothe previous A/N feedback or compared to the previous (e.g., recent)received NFI bit) for NFI,

3) it may be assumed/applied that a Type-2a (or Type-1 in the followingcase) codebook is indicated as the CTI,

4) in the following, it may be assumed/applied that there is nocorresponding field/signaling for “information indicating whether A/Nfeedback based on a Type-1 codebook”,

5) in the following, it may be assumed/applied that there is nocorresponding pended A/N feedback for “information indicating thepresence or absence of Pended A/N”.

(b) DCI Configuration and Signaling Information when Configuring Type-1A/N Codebook

1) Information Signaled Through DL Grant DCI

A. Basically, it may include the following information (for convenience,basic information).

i. Information indicating whether to fallback A/N

ii. Notes

1. The information may indicate whether only one fallback DCI schedulingPCell (PDSCH transmission through the PCell) is transmitted during onebundling window period. The information can be configured/signaled withonly 1-bit.

B. It may additionally include the following information.

i. Whether to configure/transmit A/N feedback based on a Type-3 codebook(e.g., CTI signaling indicating which A/N codebook to configure/transmitamong Type-1 and Type-3)

ii. Notes

1. If Type-3 is indicated through DCI (at the specific time), NFIinformation for Type-3 codebook-based A/N feedback may be additionallysignaled through a corresponding DCI.

C. It may additionally include the following information.

i. Information indicating the presence or absence of Pended A/N

ii. Notes

1. The information may indicate whether the final A/N feedback isconfigured by further including A/N with a pending indication (at theprevious time) (i.e., pended A/N) in an A/N payload configured based ona Type-1 codebook.

D. In relation to Fallback DCI-based DL Scheduling

i. Basically, a corresponding DCI format (at least corresponding to aPCell/PSCell) may have a form in which the basic information isincluded/signaled.

ii. Additionally, a fallback DCI format corresponding to a SCell (exceptfor a PCell/PSCell) may have a form in which the basic information isnot included/signaled.

E. In relation to CB group (CBG) based DL transmission operation

i. When CC/cell in which CBG based DL transmission is configured or whenCA including a CC/cell in which CBG based DL transmission is configured,a pended A/N payload may be determined based on the maximum number of(transmissible) CBGs configured for all cells/CCs, that is, the maximumvalue among the number of (transmissible) CBGs configured for eachcell/CC. When a CC/cell in which TB based transmission is configured, orwhen only CCs/cells in which TB based transmission is configured areaggregated, a pended A/N payload may be determined based on the maximumnumber of (transmissible) TBs configured for all cells/CCs, that is, themaximum value among the number of (transmissible) TBs configured foreach cell/CC.

2) Information Signaled Through UL Grant DCI

A. Basically, it may include the following information (for convenience,basic information).

i. Information indicating whether A/N feedback based on a Type-1codebook

ii. Notes

1. The information may indicate whether to transmit be piggyback an A/Npayload configured based on a type-1 codebook to a PUSCH (or whether topiggyback 0-bit (i.e., omit piggyback) or just fallback A/N) andtransmit it.

B. It may further include the following information.

i. Whether to configure/transmit A/N feedback based on a Type-3 codebook(e.g., indicate which A/N codebook to configure/transmit among Type-1and Type-3)

ii. Notes

1. If Type-3 is indicated through DCI (at the specific time), NFIinformation for Type-3 codebook-based A/N feedback may be furthersignaled through the DCI.

C. It may further include the following information.

i. Information indicating the presence or absence of Pended A/N

ii. Notes

1. The information may indicate whether the final A/N feedback isconfigured by further including A/N with a pending indication (at theprevious time) (i.e., pended A/N) in an A/N payload configured based ona Type-1 codebook.

D. In relation to Fallback DCI-based UL Scheduling

i. Basically, a fallback DCI format may have a form in which the basicinformation is not included/signaled.

ii. For information not included/signaled in UL grant DCI, a UE mayoperate to configure/transmit an A/N codebook (payload) based on themost recently detected/received information (e.g., informationindicating whether fallback A/N, a CTI, information indicating thepresence or absence of pended A/N) through DL grant DCI. Here, DL grantDCI related to the recently detected/received information may be limitedto only DCI indicating the PUSCH transmission time (slot) scheduledthrough UL grant DCI for the HARQ-ACK transmission time for a PDSCH.

iii. Meanwhile, an A/N may be piggybacked and transmitted through aCG-PUSCH transmitted without DCI in a CG (Configured Grant) form ratherthan scheduling accompanying dynamic grant DCI transmission. In thiscase, a UE may configure/transmit an A/N codebook (payload) based on themost recently detected/received information (e.g., informationindicating whether fallback A/N, a CTI, information indicating thepresence or absence of pended A/N) through DL grant DCI. Here, DL grantDCI related to the recently detected/received information may be limitedto only DCI indicating the CG-PUSCH transmission time (slot) for theHARQ-ACK transmission time for a PDSCH.

E. In relation to CB group (CBG) based DL transmission operation

i. Similar to the case of the DL grant DCI above, a pended A/N payloadmay be determined based on the maximum number of (transmittable) CBGs orTBs configured in all cells/CCs.

Meanwhile, (Type-2a or Type-1 A/N codebook configuration and accordingto this) an DL/UL grant DCI information configuration and signalingoperation may be limited to a case in which a PUCCH cell/CC (e.g., PCellor PSCell) configured to perform PUCCH transmission in a CA situation isa cell/CC operating on a U-band. In this case, DL/UL grant DCIcorresponding to all cells/CCs in CA may be configured according to themethod proposed in the present disclosure. Meanwhile, when a PUCCHcell/CC is a cell/CC operating on an L-band (in the state in which theexisting Type-1 or Type-2 A/N codebook is configured), the same DL/ULgrant DCI information configuration and signaling operation as existingone may be applied. In this case, DL/UL grant DCI corresponding to allaggregated cells/CCs may be configured the same as existing one.

As another method, Type-2a or Type-1 A/N codebook configuration andconfiguration/signaling of DL/UL grant DCI information according to thismay be limited to a case in which a cell/CC operating on a U-band isincluded in a multi-carrier, that is, a set of a plurality of cells/CCsconfigured as CA to a UE. In this case, DL/UL grant DCI corresponding toall aggregated cells/CCs may be configured as in the above-describedproposed method. Meanwhile, when multi-carrier includes only a cell/CCoperating on a L-band, the existing Type-1 or Type-2 A/N codebookconfiguration and configuration/signaling of the existing DL/UL grantDCI information according to this may be applied. In this case, DL/ULgrant DCI corresponding to all aggregated cells/CCs may be configuredthe same as existing one.

(5) Proposed Method 4

(a) A/N Feedback Update for a Specific PDSCH

For a specific PDSCH or HARQ process ID, a processing time (required forPDSCH decoding and A/N preparation operation) may be insufficientlyscheduled/indicated from a base station (compared to the minimumprocessing time that a UE can support). In this case, a UE may operateto feeds back a NACK (or DTX) for a corresponding PDSCH (or HARQ processID) through the (first) A/N (PUCCH) transmission time indicated by DCI(corresponding to a corresponding PDSCH).

Thereafter, (in a situation where there is no separate retransmissionscheduling from a base station for the PDSCH (or HARQ process ID))(Type-2a codebook-based) A/N feedback transmission for a slot group IDincluding the PDSCH or (Type-3 codebook-based) A/N feedback transmissionfor a HARQ process group including the HARQ process ID may be (again)indicated from a base station. In this case, a UE may update A/Nfeedback for a corresponding PDSCH (or HARQ process ID) by reflectingthe actual/final decoding result of a corresponding PDSCH (or HARQprocess ID). For example, when a decoding result is an ACK, an ACK for acorresponding PDSCH (or HARQ process ID) may be fed back through the A/N(PUCCH) transmission time indicated (again) from a base station.

Meanwhile, the above operation may be applied regardless of whether ornot NFI toggling corresponding to a PDSCH (or HARQ process ID), orapplied only in one case among a case in which corresponding NFI isnon-toggled and a case in which corresponding NFI is toggled. In thiscase, in another case, the feedback update as described above may beomitted (e.g., the previous feedback is maintained).

Additionally, when a processing time for a HARQ process ID isinsufficiently scheduled/indicated from a base station, an update(hereinafter, updated feedback) of HARQ-ACK feedback transmitted by a UEthrough the corresponding HARQ-ACK transmission time may vary accordingto an NDI value indicated for the corresponding HARQ process ID. Forexample, in a situation in which an NDI value is not toggled (comparedto the previous value), when a UE previously fed back an ACK for acorresponding HARQ process ID and/or an actual/final PDSCH decodingresult was an ACK, a UE may update/report HARQ-ACK feedback (e.g.,updated feedback) with an ACK. As another example, in a situation inwhich an NDI value is not toggled (relative to the previous value), whena UE previously fed back a NACK for a corresponding HARQ process IDand/or an actual/final PDSCH decoding result was a NACK, a UE may reportHARQ-ACK feedback (e.g., updated feedback) with a NACK. As anotherexample, when a NDI is indicated in a toggled state (compared to theprevious value) and a new TB or PDSCH is scheduled/transmitted, due to alack of processing time for a corresponding TB or PDSCH, a UE may reportHARQ-ACK feedback (e.g., updated feedback) with an invalid value (e.g.,NACK).

(b) CBG Retransmission Set CC Related A/N Feedback

When A/N feedback transmission based on a Type-3 codebook is indicatedfrom a base station, a size of an A/N payload transmitted through aPUCCH (or PUSCH) may increase in proportion to the number of CCsconfigured for a UE, the number of HARQ processes configured for eachCC, the maximum number of TBs or the maximum number of CBGs configuredfor each CC. Among them, in particular, the number of CBGs may be afactor in rapidly increasing a size of an A/N payload compared to otherparameters, which may cause a lot of PUCCH resource overhead.

Considering the problem of increasing UL (PUCCH) resource overhead asabove, when A/N feedback transmission based on a Type-3 codebook isindicated, for a CC in which CBG based (re)transmission is configured,it may be operated to generate/map/transmit a TB-level A/N for each HARQprocess ID. Although not limited thereto, for a CC in which CBG based(re)transmission is configured, TB-level A/N may be generated bybundling A/N between CBs or between CBGs corresponding to the samesingle HARQ process ID. For example, TB-level A/N may be generated byapplying a logical AND operation between CB-level A/Ns for each of theplurality of CBs or between CBG-level A/Ns for each of the plurality ofCBGs. Through this, an A/N payload size and PUCCH resource overhead maybe reduced. Meanwhile, in a case of not A/N feedback transmission basedon a Type-3 codebook (e.g., Type-1/2 codebook), for a CC in which CBGbased (re)transmission is configured, it may be operated togenerate/map/transmit CBG-level A/N for a corresponding PDSCH (or HARQprocess ID).

Alternatively, when Type-3 codebook-based A/N feedback transmission isindicated, for a CC configured for CBG based (re)transmission, whetherto generate/transmit TB-level A/N, or to generate/transmit CBG-level A/Nmay be configured through a higher layer signal (e.g., RRC signaling).

(c) Handling for A/N Feedback Misalignment

In a situation in which A/N feedback transmission based on a Type-1codebook is configured, a UE may feedback/transmit an ACK for HARQprocess ID=X at the specific time (e.g., slot #n). Thereafter, A/Nfeedback transmission based on a type-3 codebook at another specifictime (e.g., slot #(n+K)) may be indicated from a base station to a UE.Meanwhile, when specific DCI schedules a PDSCH corresponding to HARQprocess ID=X, the specific DCI may indicate the same time as the time(e.g., slot #(n+K)) at which type-3 codebook-based A/N transmission isindicated for A/N transmission timing for the PDSCH. If a UE fails todetect the corresponding DCI, A/N feedback misalignment (e.g.,DTX-to-ACK error) may occur between a UE and a base station for HARQprocess ID=X in a type-3 codebook. This may unnecessarily result ininefficient (RLC level) retransmissions.

To solve the above problem, if the specific time (e.g., slot Y) isindicated as the type-3 codebook-based A/N transmission time, a UE doesnot expect DCI (reception) indicating slot Y as A/N transmission timingwhile scheduling PDSCH transmission (and/or scheduling an initialtransmission of a new TB (or indicating a toggled NDI value)), and mayoperate under the assumption that there is no such DCI. Accordingly,when receiving/receiving the DCI as described above, a UE may ignore theDCI. For example, a UE may not perform an operation indicated by thecorresponding DCI.

Meanwhile, for the DCI that a UE does not expect and ignore, DCI thatschedules PDSCH transmission and at the same time indicates type-3codebook-based A/N transmission may be excluded. That is, the UE mayperform a corresponding operation without ignoring the correspondingDCI. For example, a UE may configure/transmit type-3 codebook-based A/Nfeedback including an A/N for PDSCH scheduled by the corresponding DCI.

(d) PDSCH Processing in which A/N Pending is Indicated

First, in a state in which a Type-1 A/N codebook method is configured toa UE, when a PDSCH in which A/N pending is indicated through specific DLgrant DCI (e.g., in a form in which an A/N timing for a PDSCH isindicated as invalid or non-numeric value), for A/N feedback(hereinafter, pended A/N) for the corresponding PDSCH, 1) a form oftransmitting (by a UE) the corresponding pended A/N in a form of aType-3 A/N codebook by indicating a separate A/N pooling through DCI, or2) an operation of appending the corresponding pended A/N to a Type-1A/N codebook transmitted through an A/N timing indicated (e.g.,indicated in a form in which an A/N timing for a PDSCH is indicated asvalid or a numeric value) by another DL grant DCI without a separate A/Npooling may be considered. Meanwhile, when considering the operation ofconfiguring and transmitting an A/N payload in a form of appendingpended A/N to a Type-1 A/N codebook as described above, it is essentialto configure/perform mapping so that 1) the total number of pended A/Ninformation/bits to be appended, and 2) a mapping order of thecorresponding pended A/N information/bit on the A/N payload matchbetween a UE and a base station. If there is a mismatch between a UE anda base station with respect to the number/mapping of the pended A/N onthe A/N payload, since UCI decoding performance is deteriorated andserious ACK/NACK errors (e.g., NACK-to-ACK) are generated, unnecessaryPDSCH retransmission overhead and large latency may occur.

In consideration of the above problem, (maximum) pended A/Ninformation/the number of bits (e.g., P bits) that can be appended to aType-1 A/N codebook may be configured to a UE (by a base station)through RRC signaling. A UE may configure a final A/N payload by alwaysappending the corresponding P bits to a Type-1 A/N codebook regardlessof the presence or absence of an actual pended A/N. As another method,whether there is a pended A/N (or whether to appending the P bits) maybe indicated to a UE (by a base station) through a specific (e.g.,1-bit) field in DCI (e.g., DL grant). According to information indicatedby the corresponding field, a UE may configure a final A/N payload in aform that appends or does not append a pended A/N bit(s) (or thecorresponding P bits) to a Type-1 A/N codebook. As another method, aplurality of candidates (having different values including 0) for theappended number of pended A/N bits P may be configured to a UE (throughRRC), and a value of one of the candidates may be indicated through aspecific field in DCI (e.g., DL grant). A terminal may configure a finalA/N payload by appending the number of bits corresponding to theindicated value to a Type-1 A/N codebook.

Meanwhile, a final A/N payload may be configured in a form in which aType-1 A/N codebook is preferentially mapped to a lower bit index partstarting with a most significant bit (MSB) (e.g., configured as a formof a first A/N sub-codebook), and then pended A/N information is mapped(to a higher bit index part) after it (e.g., configured as a form of asecond A/N sub-codebook). Additionally, in order to match a mappingorder between pended A/N information/bits on an A/N payload, through aspecific field in DCI (e.g., DL grant) indicating an A/N pendingoperation, an order value (e.g., counter-DAI) of the number of times aPDCCH/PDSCH corresponding to A/N pending indicated to a UE isscheduled/transmitted (among all PDCCH/PDSCHs for which A/N pending isindicated) may be indicated (by a base station). A UE may configure afinal A/N payload in a form of appending the configured/mapped pendedA/N bit(s) (payload) according to an order of the corresponding ordervalue (in a Type-1 A/N codebook). In this case, a field indicating theorder value in DCI (e.g., DL grant) may be applied as a field used forcounter-DAI signaling, or may be determined/considered as a field forallocating a PUCCH resource (to be used for A/N feedback transmission)(e.g., PUCCH Resource Indicator, PRI).

Meanwhile, in a state in which an A/N pending operation is indicated fora corresponding PDSCH through DCI (e.g., DL grant) at a specific time,(pended) A/N feedback for the corresponding PDSCH may be transmittedthrough an A/N timing indicated (as a Type-1 codebook-based A/N feedbacktime) from another DCI at a specific time later. In this case, it may benecessary to determine the corresponding A/N timing (to which pended A/Nis to be transmitted). For this purpose, through each DCI, whether totransmit (additionally) pended A/N (for a PDSCH in which A/N pending wasindicated at the previous time) may be directly indicated at the A/Ntiming indicated by the corresponding DCI. Here, DCI may include, forexample, DCI triggering A/N feedback based on a Type-1 codebook. Asanother method, the corresponding pended A/N may be transmitted (byappending) through the earliest among the A/N timings indicated fromDCIs (e.g., in which A/N timing for a PDSCH is indicated as valid or anumerical value) transmitted after the (DCI or PDSCH transmission) timeat which A/N pending is indicated. Here, DCI may include, for example,DCI triggering A/N feedback based on a Type-1 codebook.

Additionally, in order to prevent mismatch between a UE and a basestation for A/N payload, a method of configuring/designating the time atwhich pended A/N transmission is allowable may be considered, asdescribed above (transmitted through the same UL time by being appendedto a Type-1 A/N codebook). Specifically, when an A/N pending operationis indicated for a PDSCH transmitted in slot #n or through DCI (e.g., DLgrant) transmitted in slot #n, it may be configured/designated so thatthe corresponding pended A/N transmission is allowable only through aPUCCH (PUSCH) (carrying a Type-1 A/N codebook) transmitted through thetime (and/or the time including/before slot #(n+T+F)) including/afterslot #(n+T). In addition, when a PDSCH reception slot corresponding topended A/N coincides with slot X included in a bundling windowcorresponding to an A/N transmission timing indicated through DCI (e.g.,DL grant), a UE may configure a Type-1 A/N codebook for the bundlingwindow in a form of mapping pended A/N information/bit to an A/N bitcorresponding to slot X.

In addition, in a state in which a Type-2 A/N codebook method isconfigured to a UE, in case of a PDSCH in which A/N pending is indicatedthrough specific DL grant DCI (e.g., in a form in which an A/N timingfor a PDSCH is indicated as invalid or non-numeric value), for (pended)A/N feedback for the corresponding PDSCH, 1) an operation oftransmitting (by a UE) the corresponding pended A/N in a form of aType-3 A/N codebook by indicating a separate A/N pooling throughspecific DCI, or 2) an operation of appending the corresponding pendedA/N to a Type-2 A/N codebook transmitted through an A/N timing indicated(e.g., indicated in a form in which an A/N timing for a PDSCH isindicated as valid or a numeric value) by another DL grant DCI without aseparate A/N pooling may be considered. Meanwhile, similarly, whenconsidering the operation of configuring and transmitting an A/N payloadin a form of appending pended A/N to a Type-2 A/N codebook as describedabove, it is essential to configure/perform mapping so that 1) the totalnumber of pended A/N information/bits to be appended, and 2) a mappingorder of the corresponding pended A/N information/bit on the A/N payloadmatch between a UE and a base station (in terms of UCI decodingperformance and PDSCH retransmission overhead/latency).

In consideration of this, in order to match (between a UE and a basestation) the total number of pended A/N information/bits on an A/Npayload and a mapping order between pended A/N information/bits, througha specific field in DCI (e.g., DL grant) indicating an A/N pendingoperation, information on an order value (e.g., counter-DAI) of thenumber of times a PDCCH/PDSCH corresponding to A/N pending indicatedthrough the DCI is scheduled/transmitted (among all PDCCHs/PDSCHs forwhich A/N pending is indicated) and/or a total value (e.g., total-DAI)of the total number of PDCCHs/PDSCHs for which A/N pending is indicatedto a UE until the current time may be informed (by a base station).Accordingly, a UE may configure a final A/N payload in a form ofappending the pended A/N bit(s) (payload) (to a Type-2 A/N codebook)configured/mapped based on the corresponding total value and/oraccording to an order of the corresponding order value. Meanwhile, afinal A/N payload may be configured in a form in which a Type-2 A/Ncodebook is preferentially mapped to a lower bit index part startingwith a MSB (e.g., configured as a form of a first A/N sub-codebook), andthen pended A/N information is mapped (to a higher bit index part) afterit (e.g., configured as a form of a second A/N sub-codebook).

Meanwhile, in a state in which an A/N pending operation is indicated fora corresponding PDSCH through DCI (e.g., DL grant) at a specific time,(pended) A/N feedback for the corresponding PDSCH may be transmittedthrough an A/N timing indicated (as a Type-2 codebook-based A/N feedbacktime) from another DCI at a specific time later. In this case, it may benecessary to determine the corresponding A/N timing (to which pended A/Nis to be transmitted). For this purpose, through each DCI, whether totransmit (additionally) pended A/N (for a PDSCH in which A/N pending wasindicated at the previous time) may be directly indicated at the A/Ntiming indicated by the corresponding DCI. Here, DCI may include, forexample, DCI triggering A/N feedback based on a Type-2 codebook. Asanother method, the corresponding pended A/N may be transmitted (byappending) through the earliest among the A/N timings indicated fromDCIs (e.g., in which A/N timing for a PDSCH is indicated as valid or anumerical value) transmitted after the time (for DCI or PDSCHtransmission) at which A/N pending is indicated. Here, DCI may include,for example, DCI triggering A/N feedback based on a Type-2 codebook.

In addition, in a state in which a Type-2a A/N codebook method isconfigured to a UE, in case of a PDSCH in which A/N pending is indicated(and designated with specified (PDSCH) slot group ID=X) through specificDL grant DCI, for (pended) A/N feedback for the corresponding PDSCH, 1)pended A/N may be transmitted (by a UE) in a form of a Type-3 A/Ncodebook by indicating a separate A/N pooling through specific DCI, or2) pended A/N may be included in a Type-2a A/N codebook transmittedthrough an A/N timing indicated by another DL grant DCI (e.g. requestingA/N feedback for slot group ID=X) without a separate A/N pooling may beconsidered. Meanwhile, in the latter case, it may be necessary todetermine an A/N timing at which pended A/N feedback is transmitted. Asa method for this, pended A/N is transmitted (by appending) through theearliest among the A/N timings indicated from specific DCIs (e.g.,requesting A/N feedback for slot group ID=X (while triggering Type-2acodebook-based A/N feedback)) (e.g., in which an A/N timing for a PDSCHis indicated as valid or a numeric value) transmitted after the time(for DCI or PDSCH transmission) at which A/N pending is indicated.

Additionally, when a Type-1 or Type-2 A/N codebook method is configured,an operation of dynamically triggering A/N feedback transmission basedon a Type-3 A/N codebook method through specific DCI may beapplied/allowed. On the other hand, when a Type-2a A/N codebook methodis configured, it may be specified/defined so that DCI-based dynamicType-3 A/N codebook triggering is not applied/allowed. In addition, whena Type-1 or Type-2 A/N codebook method is configured, an A/N pendingindication operation (in a form of indicating an invalid or non-numericA/N timing value for a PDSCH) as described above through DCI (e.g., DLgrant) may not be applied/allowed. On the other hand, when a Type-2amethod is configured, it may be specified/defined so that an A/N pendingindication operation (in a form of indicating an invalid or non-numericA/N timing value) through DCI is applied/allowed.

(e) A/N Feedback Transmission Operation for SPS PDSCH

First, SPS (Semi-Persistent Scheduling) will be described. For generalunicast data (e.g., PDSCH), a resource is dynamically allocated forevery transmission by scheduling (e.g., DCI).

In contrast, SPS is a method of reserving a resource in advance fortraffic that occurs periodically with a required data rate of medium/lowspeed, such as VoIP or streaming. SPS can reduce scheduling overhead andallocate a resource stably by reserving a resource for specific trafficin advance.

FIG. 15 illustrates DL SPS transmission. In reference to FIG. 15 , SPSconfiguration information is provided by RRC (Radio Resource Control)signaling, and the SPS configuration information may include an SPSPDSCH period/offset, etc. Here, SPS configuration information mayinclude information on an SPS time resource, and the SPS time resourcemay include an SPS PDSCH period/offset, etc. A UE does not immediatelyreceive an SPS PDSCH even if the UE is allocated SPS configurationinformation by RRC signaling, and SPS activation/release is performedthrough a PDCCH. When a UE receives a PDCCH for SPS activation (SPSactivation PDCCH), the UE receives an SPS PDSCH in a slot allocated byRRC signaling. An SPS activation PDCCH carries RB allocation informationand MCS (Modulation and Coding Scheme) information for an SPS PDSCH.Thereafter, based on scheduling information in an SPS activation PDCCH,an SPS PDSCH is periodically received in accordance with an SPS PDSCHperiod without a corresponding PDCCH. Meanwhile, when a UE receives aPDCCH for SPS release (SPS release PDCCH), the UE stops receiving an SPSPDSCH. A/N information for an SPS PDSCH may be transmitted based onPUCCH resource information/HARQ timing information (e.g.,PDSCH-to-HARQ-ACK reporting offset (K1); see FIG. 6 ) in an SPSactivated PDCCH.

FIG. 16 illustrates an existing Type-2 A/N codebook method. FIG. 16 isbasically the same as FIG. 12B, except that an SPS PDSCH is added. Inreference to FIG. 16 , a UE may receive a PDSCH scheduled by DCI withDAI=00 in slot #n, and receive a PDSCH scheduled by DCI with DAI=10 inslot #(n+2). In addition, a UE may receive an SPS PDSCH in slot #(n+1).An A/N for an SPS PDSCH is appended to the end of a DAI-based A/Ncodebook. Specifically, when t-DAI=3 is signaled, a UE maygenerate/transmit A/N information only for reception of three PDSCHscorresponding to consecutive DAI values (i.e., DAI=00/01/11)(hereinafter, DAI sequence). Here, an A/N response to PDSCH receptioncorresponding to DAI=01 is processed as a NACK, and an A/N for an SPSPDSCH is appended after an A/N for a DAI sequence. In addition, whent-DAI is not signaled, a UE may generate/transmit A/N information forPDSCH reception in all slots corresponding to candidate HARQ timings. AnA/N for a DAI sequence is located at an MSB part of an A/N payload, andan A/N for an SPS PDSCH is located at the end of an A/N payload.

Meanwhile, an SPS PDSCH transmitted without a corresponding DCI (e.g.,DL grant) and A/N feedback for the SPS PDSCH in a situation where aType-2a (or Type-1 or Type-2) A/N codebook method isconfigured/indicated may be considered. For more details about a Type-2a(or Type-1 or Type-2) A/N codebook method, refer to Proposed Method 3.In this case, since a retransmission request (e.g., according to LBTfailure of a UE and/or A/N detection failure of a base station) for A/Nfeedback corresponding to an SPS PDSCH is not possible because there isno separate slot group ID designation for an SPS PDSCH, 1) A/N feedbacktransmission time for an SPS PDSCH, and 2) A/N feedbackconfiguration/mapping rule on a Type-2a A/N codebook may be required.

First, in case of A/N feedback transmission time for an SPS PDSCH, forexample, an SPS PDSCH period is configured with L slots and an A/Ntiming (delay) corresponding to an SPS PDSCH is indicated with K slots.In this case, A/N feedback for an SPS PDSCH transmitted in slot #n maybe transmitted (repeatedly) through all A/N timings indicated in aninterval from slot #(n+K) to slot #(n+K+L−1). Alternatively, Type-2a (orType-1 or Type-2) codebook-based A/N feedback for an SPS PDSCHtransmitted in slot #n is transmitted only through slot #(n+K), and itmay be (additionally) transmitted through the time indicated by a Type-3codebook-based A/N timing in an interval from slot #(n+K) to slot#(n+K+L−1). As another method, when operating in a Type-2a A/N codebookmethod, a specific (slot) group ID to which SPS PDSCHs to be transmittedlater belong may be designated through SPS activation DCI (e.g., SPSactivation PDCCH). Accordingly, when configuring/transmitting A/Nfeedback for the corresponding (slot) group ID (according to a requestfrom a base station), it may be configured/transmitted including an A/Nfor the corresponding SPS PDSCH.

FIG. 17 illustrates a problem in an A/N configuration/mapping for an SPSPDSCH on a Type-2a A/N codebook. FIG. 17 exemplifies a case in which anA/N for an SPS PDSCH and an A/N for PDSCHs for which a slot group ID isdesignated through DCI (e.g., DL grant) are configured/mapped withoutseparating them in an A/N codebook is exemplified. In reference to FIG.17 , a UE receives a PDSCH(s) corresponding to group #A (e.g., group ID#0) and a PDSCH(s) corresponding to group #B (e.g., group ID #1). Inaddition, a UE receives an SPS PDSCH in a candidate HARQ timing intervalcorresponding to group #A. It is assumed that a UE receives a requestfor A/N transmission for group #A/#B. In this case, the A/N transmissiontime for an SPS PDSCH may overlap with the A/N transmission time forgroup #A/#B. In this case, according to the conventional Type-2 A/Ncodebook method illustrated in FIG. 16 , an A/N for an SPS PDSCH may beappended to the end of A/N information for group #A.

However, A/N information for group #A/#B can be requested for A/Nretransmission, respectively, however an SPS PDSCH does not have a groupID, so an A/N retransmission request is impossible. Accordingly, an A/Npayload configuration/mapping is different when initial transmission andretransmission of A/N information for group #A/#B are performed. This isbecause when A/N information for group #A/#B is retransmitted, an SPSPDSCH may not exist or a new SPS PDSCH may exist. Due to this, forexample, as illustrated in the figure, a location of A/N information forgroup #B in an A/N payload may vary depending on the A/N transmissiontime, so a problem such as A/N mismatch between a UE and a base stationmay occur.

Therefore, in the present proposal, an A/N configuration/mapping for anSPS PDSCH on a Type-2a A/N codebook may be configured/mapped byseparating from an A/N for PDSCHs to which a slot group ID is assignedthrough DCI (e.g., DL grant). As an example, on an A/N payload of aType-2 codebook, it may be configured that an A/N for a PDSCH for whicha slot group ID is designated may be mapped to a lower bit index partstarting with a most significant bit (MSB) (e.g., configured as a formof a first A/N sub-codebook), and then an A/N for an SPS PDSCH is mapped(to a higher bit index part) after it (e.g., configured as a form of asecond A/N sub-codebook).

FIG. 18 illustrates an A/N transmission process according to anembodiment of the present disclosure. In reference to FIG. 18 , a UE mayreceive a PDSCH(s) belonging to a first PDSCH group and a PDSCH(s)belonging to a second PDSCH group (S1802). Here, a PDSCH groupcorresponds to a (slot) group, and each PDSCH group is used as a basicgroup for an A/N request. In addition, a UE may receive an SPS PDSCH(S1804). Thereafter, a UE may generate first A/N information for a firstPDSCH group and/or second A/N information for a second PDSCH group.Here, based on an A/N for an SPS PDSCH being transmitted together withthe first A/N information (and the second A/N information), the A/N forthe SPS PDSCH may be appended after the first A/N information (andsecond A/N information). Thereafter, a UE may transmit controlinformation including the first A/N information (and the second A/Ninformation) and the A/N for the SPS PDSCH (S1806). Here, controlinformation may be transmitted through a PUCCH or a PUSCH.

In addition, an SPS PDSCH may be generalized to a specific PDSCH thatdoes not belong to any PDSCH group (i.e., a PDSCH without a designatedgroup ID). In addition, although A/N retransmission is allowed for thefirst and second A/N information, respectively, but A/N retransmissionmay not be allowed for the A/N for the SPS PDSCH. In addition, receivingDCI for PDSCH scheduling may be further included, and the DCI mayinclude A/N request information for the first PDSCH group and A/Nrequest information for the second PDSCH group. In addition, theproposed method may be limitedly applied when operating in an unlicensedband (e.g., a shared spectrum). For example, the control information maybe transmitted in an unlicensed band.

FIG. 19 illustrates an A/N payload configuration according to anembodiment of the present disclosure. The PDSCH reception situation ofFIG. 17 is assumed, and an A/N payload configuration is possible as apart of FIG. 18 . Abase station may request from a UE (case 1) onlyfirst A/N information for a first PDSCH group (e.g., group #A), or (case2) only second A/N information for a second PDSCH group (e.g., group#B), or (case 3) an A/N for both first and second PDSCH groups.Accordingly, in an A/N payload, an A/N for each group and an A/N for anSPS PDSCH may be configured as follows.

-   -   Case 1: [A/N information for group #A]+[A/N for an SPS PDSCH]    -   Case 2: [A/N information for group #A]+[A/N for an SPS PDSCH]    -   Case 3: [A/N information for groups #A/#B]+[A/N for an SPS        PDSCH]

In addition, an A/N configuration/mapping for an SPS PDSCH on a Type-3A/N codebook may be configured/mapped separately from an A/N for PDSCHsfor which a HARQ process ID is designated through DCI (e.g., DL grant).As an example, on an A/N payload of a Type-3 codebook, it may beconfigured that an A/N for a PDSCH for which a HARQ process ID maydesignated through DCI is mapped to a lower bit index part starting witha most significant bit (MSB) (e.g., configured as a form of a first A/Nsub-codebook), and then an A/N for an SPS PDSCH is mapped (to a higherbit index part) after it (e.g., configured as a form of a second A/Nsub-codebook).

FIG. 20 illustrates a communication system 1 to which the presentdisclosure is applied.

Referring to FIG. 20 , a communication system 1 applied to the presentdisclosure includes a wireless device, a base station, and a network.Here, the wireless device means a device that performs communicationusing a wireless access technology (e.g., 5G NR (New RAT), LTE (LongTerm Evolution)), and may be referred to as a communication/wireless/5Gdevice. Although not limited thereto, the wireless device may includerobots 100 a, vehicles 100 b-1 and 100 b-2, an extended reality (XR)device 100 c, a hand-held device 100 d, and a home appliance 100 e. anInternet of Thing (IoT) device (100 f), and an AI device/server 400. Forexample, the vehicle may include a vehicle equipped with a wirelesscommunication function, an autonomous driving vehicle, a vehicle capableof performing inter-vehicle communication, and the like. Here, thevehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone).The XR device includes AR (Augmented Reality)/VR (Virtual Reality)/MR(Mixed Reality) devices, and it may be implemented in the form of a HMD(Head-Mounted Device), a HUD (Head-Up Display) in a vehicle, a TV, asmartphone, a computer, a wearable device, a home appliance, a digitalsignage, a vehicle, a robot, and the like. The hand-held device mayinclude a smart phone, a smart pad, a wearable device (e.g., a smartwatch, a smart glass), a computer (e.g., a notebook computer, etc.). Thehome appliance may include a TV, a refrigerator, a washing machine, andthe like. The IoT device may include a sensor, a smart meter, and thelike. For example, the base station and the network may be implementedas a wireless device, and the specific wireless device 200 a may operateas a base station/network node to other wireless devices.

The wireless devices 100 a to 100 f may be connected to the network 300through the base station 200. AI (Artificial Intelligence) technologymay be applied to the wireless devices 100 a to 100 f, and the wirelessdevices 100 a to 100 f may be connected to the AI server 400 through thenetwork 300. The network 300 may be configured using a 3G network, a 4G(e.g., LTE) network, or a 5G (eg, NR) network, and the like. Thewireless devices 100 a to 100 f may communicate with each other throughthe base station 200/network 300, but may communicate directly (e.g.sidelink communication) without passing through the basestation/network. For example, the vehicles 100 b-1 and 100 b-2 mayperform direct communication (e.g. V2V (Vehicle to Vehicle)/V2X (Vehicleto everything) communication). In addition, the IoT device (e.g.,sensor) may directly communicate with other IoT devices (e.g., sensors)or other wireless devices 100 a to 100 f.

Wireless communication/connections 150 a, 150 b, and 150 c may beestablished between the wireless devices 100 a to 100 f/base station 200and the base station 200/base station 200. Here, wirelesscommunication/connection may be achieved through various wireless accesstechnologies (e.g. 5G NR) such as uplink/downlink communication 150 a,sidelink communication 150 b (or D2D communication), base stationcommunication 150 c (e.g., relay, Integrated Access Backhaul (IAB)).Through wireless communication/connections 150 a, 150 b, 150 c, thewireless device and the base station/wireless device, and the basestation and the base station can transmit/receive radio signals to eachother. For example, the wireless communication/connection 150 a, 150 b,150 c may transmit/receive signals through various physical channels. Tothis end, based on various proposals of the present disclosure, fortransmitting/receiving radio signals, at least some of a process ofconfiguring various configuration information, various signal processingprocesses (e.g., channel encoding/decoding, modulation/demodulation,resource mapping/demapping, etc.), and resource allocation process maybe performed.

FIG. 21 illustrates a wireless device to which the present disclosure isapplied.

In reference to FIG. 21 , a first wireless device 100 and a secondwireless device 200 may transmit and receive a wireless signal through avariety of radio access technologies (e.g., LTE, NR). Here, {firstwireless device 100, second wireless device 200} may correspond to{wireless device 100 x, base station 200} and/or {wireless device 100 x,wireless device 100 x} of FIG. 20 .

A first wireless device 100 may include one or more processors 102 andone or more memories 104 and may additionally include one or moretransceivers 106 and/or one or more antennas 108. A processor 102 maycontrol a memory 104 and/or a transceiver 106 and may be configured toimplement description, functions, procedures, proposals, methods and/oroperation flow charts included in the present disclosure. For example, aprocessor 102 may transmit a wireless signal including firstinformation/signal through a transceiver 106 after generating firstinformation/signal by processing information in a memory 104. Inaddition, a processor 102 may receive a wireless signal including secondinformation/signal through a transceiver 106 and then store informationobtained by signal processing of second information/signal in a memory104. A memory 104 may be connected to a processor 102 and may store avariety of information related to an operation of a processor 102. Forexample, a memory 104 may store a software code including commands forperforming all or part of processes controlled by a processor 102 or forperforming description, functions, procedures, proposals, methods and/oroperation flow charts included in the present disclosure. Here, aprocessor 102 and a memory 104 may be part of a communicationmodem/circuit/chip designed to implement a wireless communicationtechnology (e.g., LTE, NR). A transceiver 106 may be connected to aprocessor 102 and may transmit and/or receive a wireless signal throughone or more antennas 108. A transceiver 106 may include a transmitterand/or a receiver. A transceiver 106 may be used together with a RF(Radio Frequency) unit. In the present disclosure, a wireless device maymean a communication modem/circuit/chip.

A second wireless device 200 may include one or more processors 202 andone or more memories 204 and may additionally include one or moretransceivers 206 and/or one or more antennas 208. A processor 202 maycontrol a memory 204 and/or a transceiver 206 and may be configured toimplement description, functions, procedures, proposals, methods and/oroperation flows charts included in the present disclosure. For example,a processor 202 may generate third information/signal by processinginformation in a memory 204, and then transmit a wireless signalincluding third information/signal through a transceiver 206. Inaddition, a processor 202 may receive a wireless signal including fourthinformation/signal through a transceiver 206, and then store informationobtained by signal processing of fourth information/signal in a memory204. A memory 204 may be connected to a processor 202 and may store avariety of information related to an operation of a processor 202. Forexample, a memory 204 may store a software code including commands forperforming all or part of processes controlled by a processor 202 or forperforming description, functions, procedures, proposals, methods and/oroperation flow charts included in the present disclosure. Here, aprocessor 202 and a memory 204 may be part of a communicationmodem/circuit/chip designed to implement a wireless communicationtechnology (e.g., LTE, NR). A transceiver 206 may be connected to aprocessor 202 and may transmit and/or receive a wireless signal throughone or more antennas 208. A transceiver 206 may include a transmitterand/or a receiver. A transceiver 206 may be used together with a RFunit. In the present disclosure, a wireless device may mean acommunication modem/circuit/chip.

Hereinafter, a hardware element of a wireless device 100, 200 will bedescribed in more detail. It is not limited thereto, but one or moreprotocol layers may be implemented by one or more processors 102, 202.For example, one or more processors 102, 202 may implement one or morelayers (e.g., a functional layer such as PHY, MAC, RLC, PDCP, RRC,SDAP). One or more processors 102, 202 may generate one or more PDUs(Protocol Data Unit) and/or one or more SDUs (Service Data Unit)according to description, functions, procedures, proposals, methodsand/or operation flow charts included in the present disclosure. One ormore processors 102, 202 may generate a message, control information,data or information according to description, functions, procedures,proposals, methods and/or operation flow charts included in the presentdisclosure. One or more processors 102, 202 may generate a signal (e.g.,a baseband signal) including a PDU, a SDU, a message, controlinformation, data or information according to functions, procedures,proposals and/or methods disclosed in the present disclosure to provideit to one or more transceivers 106, 206. One or more processors 102, 202may receive a signal (e.g., a baseband signal) from one or moretransceivers 106, 206 and obtain a PDU, a SDU, a message, controlinformation, data or information according to description, functions,procedures, proposals, methods and/or operation flow charts included inthe present disclosure.

One or more processors 102, 202 may be referred to as a controller, amicro controller, a micro processor or a micro computer. One or moreprocessors 102, 202 may be implemented by a hardware, a firmware, asoftware, or their combination. In an example, one or more ASICs(Application Specific Integrated Circuit), one or more DSPs (DigitalSignal Processor), one or more DSPDs (Digital Signal Processing Device),one or more PLDs (Programmable Logic Device) or one or more FPGAs (FieldProgrammable Gate Arrays) may be included in one or more processors 102,202. Description, functions, procedures, proposals, methods and/oroperation flow charts included in the present disclosure may beimplemented by using a firmware or a software and a firmware or asoftware may be implemented to include a module, a procedure, afunction, etc. A firmware or a software configured to performdescription, functions, procedures, proposals, methods and/or operationflow charts included in the present disclosure may be included in one ormore processors 102, 202 or may be stored in one or more memories 104,204 and driven by one or more processors 102, 202. Description,functions, procedures, proposals, methods and/or operation flow chartsincluded in the present disclosure may be implemented by using afirmware or a software in a form of a code, a command and/or a set ofcommands.

One or more memories 104, 204 may be connected to one or more processors102, 202 and may store data, a signal, a message, information, aprogram, a code, an instruction and/or a command in various forms. Oneor more memories 104, 204 may be configured with ROM, RAM, EPROM, aflash memory, a hard drive, a register, a cash memory, a computerreadable storage medium and/or their combination. One or more memories104, 204 may be positioned inside and/or outside one or more processors102, 202. In addition, one or more memories 104, 204 may be connected toone or more processors 102, 202 through a variety of technologies suchas a wire or wireless connection.

One or more transceivers 106, 206 may transmit user data, controlinformation, a wireless signal/channel, etc. mentioned in methods and/oroperation flow charts, etc. of the present disclosure to one or moreother devices. One or more transceivers 106, 206 may receiver user data,control information, a wireless signal/channel, etc. mentioned indescription, functions, procedures, proposals, methods and/or operationflow charts, etc. included in the present disclosure from one or moreother devices. For example, one or more transceivers 106, 206 may beconnected to one or more processors 102, 202 and may transmit andreceive a wireless signal. For example, one or more processors 102, 202may control one or more transceivers 106, 206 to transmit user data,control information or a wireless signal to one or more other devices.In addition, one or more processors 102, 202 may control one or moretransceivers 106, 206 to receive user data, control information or awireless signal from one or more other devices. In addition, one or moretransceivers 106, 206 may be connected to one or more antennas 108, 208and one or more transceivers 106, 206 may be configured to transmit andreceive user data, control information, a wireless signal/channel, etc.mentioned in description, functions, procedures, proposals, methodsand/or operation flow charts, etc. included in the present disclosurethrough one or more antennas 108, 208. In the present disclosure, one ormore antennas may be a plurality of physical antennas or a plurality oflogical antennas (e.g., an antenna port). One or more transceivers 106,206 may convert a received wireless signal/channel, etc. into a basebandsignal from a RF band signal to process received user data, controlinformation, wireless signal/channel, etc. by using one or moreprocessors 102, 202. One or more transceivers 106, 206 may convert userdata, control information, a wireless signal/channel, etc. which areprocessed by using one or more processors 102, 202 from a basebandsignal to a RF band signal. Therefor, one or more transceivers 106, 206may include an (analogue) oscillator and/or a filter.

FIG. 22 illustrates another example of a wireless device to which thepresent disclosure is applied. Wireless devices can be implemented invarious forms depending on use-examples/services. (See FIG. 20 )

Referring to FIG. 22 , the wireless devices 100 and 200 correspond tothe wireless devices 100 and 200 of FIG. 21 , and may be composed ofvarious elements, components, units and/or modules. For example, thewireless devices 100 and 200 may include a communication unit 110, acontrol unit 120, a memory unit 130, and additional components 140. Thecommunication unit may include a communication circuit 112 and atransceiver(s) 114. For example, the communication circuit 112 mayinclude one or more processors 102 and 202 and/or one or more memories104 and 204 of FIG. 21 . For example, the transceiver(s) 114 may includeone or more transceivers 106, 206 and/or one or more antennas 108, 208of FIG. 21 . The control unit 120 is electrically connected to thecommunication unit 110, the memory unit 130, and the additionalcomponents 140 and controls all operations of the wireless device. Forexample, the control unit 120 may control the electrical/mechanicaloperation of the wireless device based on theprogram/code/command/information stored in the memory unit 130. Inaddition, the control unit 120 may transmit the information stored inthe memory unit 130 to an external (e.g., other communication device)through the communication unit 110 through a wireless/wired interface,or store information received through a wireless/wired interface from anexternal device (e.g., another communication device) through thecommunication unit 110 in the memory unit 130.

The additional components 140 may be variously configured according tothe type of wireless device. For example, the additional components 140may include at least one of a power unit/battery, a I/O unit, a drivingunit, and a computing unit. Although not limited to this, the wirelessdevice may be implemented in the form of a robot (FIG. 20, 100 a),vehicles (FIG. 20, 100 b-1, 100 b-2), a XR device (FIG. 20, 100 c), amobile device (FIG. 20, 100 d), an appliance (FIG. 20, 100 e), an IoTdevice (FIG. 20, 100 f), a digital broadcasting terminal, a hologramdevice, a public safety device, a MTC device, a medical device, aFinTech device (or financial device), a security device, aclimate/environment device, an AI server/device (FIG. 20, 400 ), a basestation (FIG. 20, 200 ), and a network node and the like. The wirelessdevice may be used in a mobile or fixed place depending on theuse-example/service.

In FIG. 22 , various elements, components, units, and/or modules in thewireless devices 100 and 200 may be entirely interconnected through awired interface, or at least some may be wirelessly connected throughthe communication unit 110. For example, in the wireless devices 100 and200, the control unit 120 and the communication unit 110 may beconnected by wire, and the control unit 120 and the first unit (e.g.,130, 140) may be connected wirelessly through the communication unit110. In addition, each element, component, unit, and/or module in thewireless device 100 and 200 may further include one or more elements.For example, the control unit 120 may be composed of one or moreprocessor sets. For example, the control unit 120 may be composed of aset of a communication control processor, an application processor, anelectronic control unit (ECU), a graphic processing processor, and amemory control processor. As another example, the memory unit 130 may becomposed of a random access memory (RAM), a dynamic RAM (DRAM), a readonly memory (ROM), a flash memory, a volatile memory, and a non-volatilememory and/or a combination thereof.

FIG. 23 illustrates a vehicle or an autonomous driving vehicle to whichthe present disclosure is applied. The vehicle or the autonomous drivingvehicle may be implemented as a mobile robot, a vehicle, a train, anaerial vehicle (AV), a ship, and the like.

Referring to FIG. 23 , the vehicle or the autonomous driving vehicle 100may include an antenna unit 108, a communication unit 110, a controlunit 120, a driving unit 140 a, a power supply unit 140 b, a sensor unit140 c and an autonomous driving unit 140 d. The antenna unit 108 may beconfigured as a part of the communication unit 110. Blocks 110/130/140a-140 d correspond to blocks 110/130/140 of FIG. 22 , respectively.

The communication unit 110 may transmit and receive signals (e.g., data,control signals, etc.) with external devices such as other vehicles,base stations (e.g., base stations, roadside units, etc.), servers, andthe like. The control unit 120 may perform various operations bycontrolling elements of the vehicle or the autonomous driving vehicle100. The control unit 120 may include an Electronic Control Unit (ECU).The driving unit 140 a may cause the vehicle or the autonomous drivingvehicle 100 to run on the ground. The driving unit 140 a may include anengine, a motor, a power train, a wheel, a brake, a steering device, andthe like. The power supply unit 140 b supplies power to the vehicle orthe autonomous driving vehicle 100, and may include a wired/wirelesscharging circuit, a battery, and the like. The sensor unit 140 c mayobtain vehicle status, surrounding environment information, userinformation, and the like. The sensor unit 140 c may include an inertialmeasurement unit (IMU) sensor, a collision sensor, a wheel sensor, aspeed sensor, an inclination sensor, a weight sensor, a heading sensor,a position module, a vehicle forward/reverse sensor, a battery sensor, afuel sensor, a tire sensor, a steering sensor, a temperature sensor, ahumidity sensor, an ultrasonic sensor, an illuminance sensor, a pedalposition sensor, and the like. The autonomous driving unit 140 d mayimplement a technology for maintaining a driving lane, a technology forautomatically adjusting speed such as adaptive cruise control, atechnology for automatically driving along a predetermined route, atechnology for automatically setting a route when a destination is set,etc.

For example, the communication unit 110 may receive map data, trafficinformation data, and the like from an external server. The autonomousdriving unit 140 d may generate an autonomous driving route and adriving plan based on the acquired data. The control unit 120 maycontrol the driving unit 140 a to move the vehicle or the autonomousdriving vehicle 100 along the autonomous driving path (e.g.,speed/direction adjustment) according to the driving plan. Duringautonomous driving, the communication unit 110 may obtain the latesttraffic information data from an external serveraperiodically/periodically, and may acquire surrounding trafficinformation data from surrounding vehicles. Also, during autonomousdriving, the sensor unit 140 c may acquire vehicle state and surroundingenvironment information. The autonomous driving unit 140 d may updatethe autonomous driving route and driving plan based on the newlyacquired data/information. The communication unit 110 may transmitinformation about a vehicle location, an autonomous driving route, adriving plan, and the like to an external server. The external servermay predict traffic information data in advance using AI technology orthe like based on information collected from the vehicle or theautonomous driving vehicles, and may provide the predicted trafficinformation data to the vehicle or autonomous driving vehicles.

Embodiments described above are that elements and features of thepresent disclosure are combined in a predetermined form. Each element orfeature should be considered to be optional unless otherwise explicitlymentioned. Each element or feature may be implemented in a form that itis not combined with other element or feature. In addition, anembodiment of the present disclosure may include combining a part ofelements and/or features. An order of operations described inembodiments of the present disclosure may be changed. Some elements orfeatures of one embodiment may be included in other embodiment or may besubstituted with a corresponding element or a feature of otherembodiment. It is clear that an embodiment may include combining claimswithout an explicit dependency relationship in claims or may be includedas a new claim by amendment after application.

It is clear to a person skilled in the pertinent art that the presentdisclosure may be implemented in other specific form in a scope notgoing beyond an essential feature of the present disclosure.Accordingly, the above-described detailed description should not berestrictively construed in every aspect and should be considered to beillustrative. A scope of the present disclosure should be determined byreasonable construction of an attached claim and all changes within anequivalent scope of the present disclosure are included in a scope ofthe present disclosure.

The present disclosure can be used in a terminal, a base station, orother equipment of a wireless mobile communication system.

What is claimed is:
 1. A method performed by a user equipment (UE) in awireless communication system, the method comprising: receiving downlinkcontrol information (DCI) for scheduling physical downlink sharedchannel (PDSCH), wherein the DCI includes a first PDSCH group index,wherein a second PDSCH group index is determined based on the firstPDSCH group index, and wherein the DCI includes a first new feedbackindicator (NFI) value corresponding to the first PDSCH group and asecond NFI value corresponding to the second PDSCH group; generatingfirst HARQ-ACK information related to the first NFI value and secondHARQ-ACK information related to the second NFI value; based on thirdHARQ-ACK information corresponding to a semi-persistent scheduling (SPS)PDSCH being transmitted with the first and second HARQ-ACK information,appending the third HARQ-ACK information after the first and secondHARQ-ACK information; and transmitting the first and second HARQ-ACKinformation and the third HARQ-ACK information.
 2. The method of claim1, wherein HARQ-ACK retransmission is allowed for the first and secondHARQ-ACK information, respectively, but HARQ-ACK retransmission is notallowed for the third HARQ-ACK information.
 3. The method of claim 1,wherein the first and second HARQ-ACK information and the third HARQ-ACKinformation is transmitted in an unlicensed band.
 4. A user equipment(UE) configured to operate in a wireless communication system, the UEcomprising: at least one transceiver for transmitting and receiving awireless signal; at least one processor for controlling the at least onetransceiver; and, at least one memory connected to the at least oneprocessor and storing instructions that, based on being executed by theat least one processor, perform operations comprising: receivingdownlink control information (DCI) for scheduling physical downlinkshared channel (PDSCH), wherein the DCI includes a first PDSCH groupindex, wherein a second PDSCH group index is determined based on thefirst PDSCH group index, and wherein the DCI includes a first newfeedback indicator (NFI) value corresponding to the first PDSCH groupand a second NFI value corresponding to the second PDSCH group;generating first HARQ-ACK information related to the first NFI value andsecond HARQ-ACK information related to the second NFI value; based onthird HARQ-ACK information corresponding to a semi-persistent scheduling(SPS) PDSCH being transmitted with the first and second HARQ-ACKinformation, appending the third HARQ-ACK information after the firstand second HARQ-ACK information; and transmitting the first and secondHARQ-ACK information and the third HARQ-ACK information.
 5. The UE ofclaim 4, wherein HARQ-ACK retransmission is allowed for the first andsecond HARQ-ACK information, respectively, but HARQ-ACK retransmissionis not allowed for the third HARQ-ACK information.
 6. The UE of claim 4,wherein the first and second HARQ-ACK information and the third HARQ-ACKinformation is transmitted in an unlicensed band.
 7. A base stationconfigured to operate in a wireless communication system, the basestation comprising: at least one transceiver for transmitting andreceiving a wireless signal; at least one processor for controlling theat least one transceiver; and, at least one memory connected to the atleast one processor and storing instructions that, based on beingexecuted by the at least one processor, perform operations comprising:transmitting downlink control information (DCI) for scheduling physicaldownlink shared channel (PDSCH), wherein the DCI includes a first PDSCHgroup index, wherein a second PDSCH group index is determined based onthe first PDSCH group index, and wherein the DCI includes a first newfeedback indicator (NFI) value corresponding to the first PDSCH groupand a second NFI value corresponding to the second PDSCH group; andreceiving first HARQ-ACK information related to the first NFI value andsecond HARQ-ACK information related to the second NFI value, wherein,based on third HARQ-ACK information corresponding to a semi-persistentscheduling (SPS) PDSCH being transmitted with the first and secondHARQ-ACK information, the third HARQ-ACK information is appended afterthe first and second HARQ-ACK information.